Unit 3 Adaptive Immunity Flashcards Preview

Microbiology 350 > Unit 3 Adaptive Immunity > Flashcards

Flashcards in Unit 3 Adaptive Immunity Deck (90):
1

This type of immunity helps if innate immunity isn't enough to clear an infection. It is found in jawed or higher vertebrates.

Is it specific or non-specific for individual foreign molecules

Adaptive Immunity

Highly specific

2

What other important quality does the adaptive immunity have?

Memory of previous exposures, providing long term protection against re-exposure to the same pathogens

3

What type of cells are B cells and T cells?

Lymphocytes (like NK cells)

4

What are the names of receptors on T cells and B cells?

What are they specific for (what do they recognize on microbe?)

Do they work together?

TCR and BCR

Epitopes

Yes, on the same epitopes even

5

These are portions of antigens that are actually responded to

Epitopes

6

These receptors can only bind with epitope fragments, can't bind when they're still on the microbe, must be presented with that fragment

These can

TCR

BCR

7

This has an IgD antibody (binds IgD), IgD antibody becomes secreted more frequently after it attaches initially

BCR

8

Only _______ can bind antigens, which are on the surface of pathogens

The smallest part of an antigen that can be recognized is the __, its a clustering of AAs

Is there only one epitope or multiple on an antigen?

The B cell reacts with an epitope with a certain antibody, and that antibody is ultimately secreted

Immune receptors

Epitope

Multiple different epitopes, each capable of stimulating a response

9

Where do B cells and T cells originate?

T cells migrate in a still immature stage to the ___ for further development

What do T cells learn in this place?

The bone marrow

Thymus Gland

Tolerance of body cell proteins

10

The bone marrow and thymus are ____ ____ organs

Generative Lymphoid Organs

11

During development, gene rearrangements produce a very large number of ____ and ____ to increase the chances of a reaction against pathogens, they are formed before exposure to pathogens

TCRs and BCRs

Also very diverse between different people, beneficial to our species

12

Once mature, lymphocytes are expelled into the peripheral blood stream as mature, _____ lymphocytes

These cells migrate through ____ tissues distributed around the body, ready to respond to threats

naive

Lymphoid Tissues

13

This is the second role of lymphocytes, other than immunity

This is the third role of them in the digestive system, they absorb lipids from foods we eat

Absorbs excess tissue fluids (like in elephantitis)

Lacteals

14

What causes lymphocytes to move around?

Muscle contraction (bodily movement)

15

What are the primary lymphoid organs

Bone marrow and thymus

16

What does 'naive' lymphocytes mean?

Not yet encountered epitope receptor they are specific for

17

Tonsils, spleen, lymph nodes, appendix, tespeyer's patches areissues (have many lymphocy

Secondary Lymphoid Tissues

18

This is a response after the primary response in adaptive immunity

Anamnestic (booster, memory)

19

What is the main difference between the primary and anamnestic response?

The primary response produces ___ lymphocytes as a result

Days following response, 7-14 days for primary

Memory lymphocytes (Memory B and T cells)

20

One of the important players of the adaptive immune response, multiple types are involved

They are involved with cell mediated side of adaptive immunity (aka destroy infected body cell, intracellular colonizer), B cells aren't involved

They can also be involved in humoral response (extracellular), aka antibody response

T cells

21

What are the three things that activation of T cells requires

Antigen Presentation
Cell signaling
Production of stimulatory responses

22

Activated T cells expand and differentiate into their ___ cells or ____ cells

Effector, Memory

aka clones

23

What are the three types of antigen presenting cells (like to T cells)

Macrophages
Dendritic Cells
B cells

24

Cell signaling, required for activation of T cells, involves what molecules?

Cytokines

25

These type of differentiated T cells work immediately

These work later on, are in reserve for later for fast response

Effector

Memory cells

26

A naive cell must interact with ____ to become dactivate

This triggers...

Antigen presenting cell

Differentiation into effector and memory cells (clonal expansion)

27

T cell activation requires binding of the TCR with the specific peptide presented on ____ molecules of APCs

Can APCs be body cells?

MHC molecules (a presentation complex with epitope)

Yes if they are infected by an intracellular colonizer, presents fragments growing inside of it

28

These are special groups of APCs for extracellular colonizers

Macrophage
Dendritic cell
B cell

29

T cells are very specific because they are produced in the ___ and mature in the _____

They are screened to avoid excessive ____

Good T cells with anti-foreign molecule TCRs are released into the

Bone Marrow, Thymus

Self-reactivity

Peripheral blood stream

30

Does one T cell have multiple receptor types or just many of one receptor?

Many of one receptor

31

How can one APCsactivate multiple different types of T cells?

They present multiple different epitope fragments with all of its MHCs

32

Co receptors on T cells also must correctly interact with the MHC molecule. It helps provide the correct ______ signal to the correct type of T cell

This type interacts with MHC class II

This type interacts with MHC class I

Activation

CD4 (helper T)

CD8 (killer T ,or cytotoxic T, Tc)

33

There are two types of helper Ts (CD4 cells)

This type stimulates cellular immune responses, good for intracellular colonizers

This type stimulates humoral (antibody) responses

TH1

TH2

34

So a T cell has a TCR and a co-receptor, the TCR binds to the ___ and the coreceptor binds to the ____

Epitope

MHC complex

35

Which cells have MHC II complexes?

Macrophages, Dendritic cells, B cells

36

Establishing memory of previous exposure is a hallmark of ___ immunity

_____ cells differentiate during initial adaptive immune responses. They are long lived, produce a faster and more rigorous response when the same antigen is encountered again, and the speed of the 2nd, 3rd, 4th, response can even prevent a repeat infection from occurring

Adaptive

Memory cells

37

These are the action cells, which are short lived and armed with direct immune functions

Effector cells

38

In T cells, effector form depends on co receptors.

In CD4+ T cells, secretion of large amounts of _____ enhance and direct actions of OTHER immune cells

In CD8+ T cells, cytotoxic killing of infected cells by release of ______ near contacted target the cell, initiating apoptosis. Part of cellular immune response

Cytokines

Granzymes/perforin (similar to NK cells)

39

In CD4 T cells, an antigen presenting cell, could be a body cell, is binded (twice, once epitope once MHC) by the T cell. The activated CD4 T cell secretes ____ and expression its receptor for autostimulation of that molecule

Clonal expansion and differentiation produces a population of memory and effector TH cells

Interleukin-2 (IL-2)

40

This term means the cell releases a chemical which binds back to itself repeatedly, it actually makes more receptors for the chemical as well. Afterwards it divides and differentiation occurs

Autostimulation

41

In intracellular antigens and the endogenous pathway, ___ t cells are used

CD8 T cells (Killer T cells)

42

Killer T cells recognize targets by their presentation of antigen epitope fragments on ______

Killing is achieved by T cell release of ______, inducing apoptosis in a target

MHC 1

Perforin/Granzyme

43

So in CD8 T cells, antigen presentation and binding by the CD8 T cell occurs to the dendritic cell or macrophage

The activated CD8 cell expresses a ____ receptor that binds ____ produced from TH cells

Clonal expansion and diffrentiation produces a population of memory and effector Tc cells

interleukin-2 receptor

IL-2

44

Which cells communicate with the activated Killer T cells? TH1 or TH2? The CD8 T cells will then divide

TH1 helper T cell

45

The cytotoxic T cell that was made from clonal expansion recognizes infected body cells by binding to the...

Which binds first? TCR or CD8 co receptor?

Do they both bind the MHC 1?

What occurs to kill the body cell?

The cell contents are degraded by

MHC 1 peptide complex with the epitope derived from the infecting microbe

TCR

Yes

Degranulation

Phagocytes

46

These are phagocytic cells that are very efficient at antigen reuptake, and thereby function as APCs. They are named for many long cytoplasmic extensions that resemble nerve dendrites

What cells are they made from?

They are formed where?

Dendritic cells

Monocytes

Bone Marrow

47

The innate functions of these cells include phagocytosis and intracellular killing

Macrophages

48

The APC functions of macrophages include presentations to memory ______ and ________ T cell subsets in secondary responses

What else can they do?

CD4 and CD8

Determine the course of CD4 T-cell differentiation into particular subsets

49

These cells are critical for adaptive immunity.

They produce ______

Also present MHC ____ peptide on their surface to CD4 Tcells

B cell

antibody

MHC II

50

What is the B cell receptor?

B cell receptors trap foreign _____

It is ingested and broken into fragments. They are loaded onto MHC class ____ molecules

Presentation to CD4 T cells occurs on TCR, causing them to secrete _____

IgD

antigen

II

cytokines

51

These help the B cell to differentiate into an antibody secreting plasma cell or a memory B cell

Cytokines

52

Most B cells need the help of T cell ____ to become fully activated, and they can't get it without presenting antigens

Cytokines

53

Cytokine secretion by Th cells is required for activities of ___ cells and ____ cells

But antibodies from them won't directly help kill or directly kill them, respectively.

Because of the different immunity needs, there are two broad types of responses. What are they?

B cells and Tc cells

Humoral Immunity

Cell-mediated Immunity

54

This type of immune response is good against extracellular pathogens

Humoral

55

This type of immune response is good against intracellular pathogens

Cell-mediated

56

Th1 and Th2 are helper T cells that are a common link between the two types of ____ immunity

Different subsets of helper T cells help in different ways by releasing different sets of ____

Which MHC do helper Ts present?

Adaptive

Cytokines

MHC II (both CD4 cells)

57

Which Th cell is involved in cellular immune responses?

Which in humoral?

TH1

TH2

58

What are the 3 responses produced by TH1 cells

Specific inflammatory response

Phagocytic Cell (macrophages/neutrophils)

Activate Killer T (CD8)

59

Fast onset inflammation is caused by

Slow onset is caused by

Histamine (innate)

TH1

60

What does TH2 talk to to stimulate the production of antibodies?

What is the APC in this instance?

B cells

B cell as well. After talking to TH2 it differentiates into plasma cell to be able to produce antibodies

61

Which cytokines can suppress the activity of TH2 cells?

What cytokines suppress the activity of TH1 cells?

TNFα, IFN-γ

IL-10 & 13

62

Which cell is responsible for inflammation that ends up damaging our own body cells? TH1 or TH2?

So which cytokine suppresses the inflammatory response

TH1

IL-10 & 13

63

Recall that our best understanding of how B cells produce antibodies is in response to protein antigens from foreign sources

These responses usually require ____ help from helper T cells

Cytokine help from helper T cells

64

To produce antigen, B cells must first bind to the foreign antigen through the BCR, then ingest it and process it. Presentation of the antigenic peptide to the TCR on the helper T cell solicits the ____ help

Which cytokines do this?

The B cell multiplies, differentiating into antibody secreting plasma cells and _______ cells.

Cytokine help

IL-4 and IL-6

Memory cells

65

In B cell responses to protein antigens, primary responses typically produce a modest amount of antibody after ______ days

Secondary responses shift to much faster and larger scale antibody production

Does the B cell retain the ability to respond to different antigens?

7-14 days

Yes

66

Plasma cells can secrete 2100+ antibodies per

Are plasma cells able to divide anymore? What is the term to describe this?

What happens to the plasma cells in about 2 days?

Do the antibodies last longer?

second

No. Terminally differentiated.

Apoptosis

Yes, for weeks even

67

Antibody production by plasma cells in specific/nonspecific

All antibodies from on eplasma cell are identical and will bind only to a single ___ on an antigen

RVery specific

Epitope

68

Recall that a single antigen may have many ____ - so many different plasma cells can be formed, each with a different specificity

Epitopes

69

This antibody (glycoprotein) has 2 heavy chains and 2 light chains forming a Y shaped structure

What type of bonds exist within and between chains?

IgG

Disulfide Bonds

70

The two arms of the Y in IgG form what?

The bottom of the Y forms what?

Antibody binding fragments (Fab) aka where epitope binds

Region that self receptors bind to

71

IgG has variable and constant regions on the heavy and light chains. Variable regions can be different between different IgG antibodies

!

72

The variable regions bind unique epitopes while the constant regions bind the same between different IgGs

!

73

A region of IgG made of the constant heavy chain and another constant heavy chain

Fc region

74

This region of IgG binds complement and Fc receptors on phagocytes to allow the white blood cell to conduct phagocytosis

The IgG acts as what?

Fc region

Opsonization factor

75

This antibody is the main part of the B cell receptor, its not released to do a job elsewhere.

IgD

76

The use of diferent C-region gene segments leads to different classes of antibodies. Each class has slightly different structures and functions in immune responses. This phenomena is called

Antibody class switching (aka phenotype switching)

77

Which antibody is always the first antibody in a primary response?

Why is IgM made first?

The complex class switching process can change the type to make the most efficient response to make what antibodies?

pentomeric IgM (p IgM)

5 IgM monomers means there are 10 binding sites

IgA,IgE, IgG

78

What are the same between the IgA, IgE, and IgE

What is different?

Variable light variable heavy chains (they must bind to the same antigen that triggered IgM production in the 1st place)

The constant region is different

79

This class of antibody is a dimer, found in tears, milk saliva, aka mucosal membranes. Also called secretory antibody.

How many binding sites, then?

IgA

Dimer = 4 binding sites

80

First type most pathogens encounter because its in the mucosal membrane...

IgA

81

This is the most abundant antibody because of the amount of surface area on mucosal membranes

IgA

82

These are monomer antibodies associated with eosinophils and allergic reactions.

IgE

83

IgEs bind to what two cell types, causing degranulation and inflammation?

What is the chemical released that causes inflammation?

Basophils and mast cells

Histamine

84

This antibody is a monomer, and is the most present antibody in the serum (in our blood) to activate complement cascade.

IgG

85

This monomer antibody can cross the placenta because its small to protect the baby.

IgG

86

The functions of antibodies

Blocks binding of pathogens/toxins on host cells (binding to the pathogen)

Fixes complement to bacterial structures for lysis

Opsonization

Agglutination

Activations eosinophils, basophils, and mast cells by providing an exposed FC region for cells to bind to

87

This is clumping of antigen caused by antibodies increasing phagocytosis

Agglutination

88

NKs respond to MHC 1 missing

NK T cell responds to epitopes presented to them on MHC 1, more specific

Both are lymphocytes

!

89

___ immunity can cause damage to our structures if it is inappropriately of excessively damaged

Adaptive

90

Th1 cells and Th2 -------> MHC II

CD8 aka killer T's have ---------> MHC I

!