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Flashcards in Adaptive Immunity Deck (66):
1

Specificity

Ensures immune response to a microbe (or nonmicrobial antigen) is targest to that microbe (or antigen)

2

Diversity

Very diverse: somatic recombination of gene segments responsible for generating array of antibodies

3

Memory

Increases ability to combat repeat infections by same microbe

4

Clonal expansion

Increases number of antigen specific lymphocytes to keep pase with microbes

5

Specialization

generates responses that are optimal for defense against different types of microbes

6

Contraction and homeostasis

Allows immune system to recover from one response so that it can effectively respond to newly encountered antigens

7

Nonreactivity to self

Prevents injury to the host during responses to foreign antigens

8

another name for determinants

epitope: the part of the antigen recognized by specific lymphocytes

9

How do lymphocytes achieve such fine ability to distinguish between antigens?

specificity and variety of cell surface receptors

10

Total number of antigenic specificities of the lymphocyte....name and number...

lymphocyte repertoire; 107-109 distinct antigenic determinants

11

Primary and Secondary immune response

Primary: slow, produces antibody
Secondary: faster, larger, qualitatively different from the first

12

Antibodies produced by primary and secondary responses: how do they differ

secondary typically have a higher affinity for the epitope than the primary antibodies

13

Memory cells versus primary response cells

memory cells have features that make them more efficient, and they operate more rapidly

14

humoral and cell mediated immunity are elicited by
different ______ or _____ and at different ______ of _____

classes of microbes or at different stages of infection

15

Contraction of immune response is called the

return to resting stage, or homeostasis

16

Why does contraction occur?

Immune responses are launched to eliminate antigens; so the process wanes as the stimulus dies

17

Tolerance is also called

non-reactivity to self

18

Nonreactivity to self is maintained via

elimination of reactive lymphoctyes, inactivating them, or suppressing them

19

Regulation of immune responses

through positive feedback loops = amplify reaction
control mechanisms = prevent inappropriate reactions

20

T lymphocytes consist of distinct subpopulations. What are they called?

helper T cells and cytotoxic (cytolytic) T lymphocytes

21

antigenic ____ causes ---> ___ cells to release ____

helper T cells to release cytokines

22

helper T cells secrete what in reaction to what?

cytokines, antigenic stimulation

23

cytokines secreted by helper T cells do what?

stimulate proliferation/differentiation of more T Cells, B cells, macrophages, and other leukocytes.

24

CTLs do what

kill cells that produce foreign antigens such as infected cells, virus infected cells or other intracellular microbes

25

Regulatory T cells: function

to suppress immune response when its unneeded

26

This is a small population of T lymphocytes that produce a cell surface protein. What is it, what's its function?

Natural killer cells (NKT)
destroy infected cells (not microbes, but infected cells)

27

APCs

antigen presenting cells

28

The most specialized APC are the

dendritic cells

29

APCs do what

capture external antigens, transport them to lymphoid organs, present to naive T lymphocytes to initiate immune response

30

Antigen elimination often requires what kind of cell?

effector cell

31

What cells are dubbed "effector cells"

mononuclear phagocytes, activated T lymphocytes, and other leukocytes

32

how does innate immune system block microbes?

Main barriers of defense include skin, lungs, and gastrointestinal tract, respiratory tract.

33

Epithelia is important, why?

main "interfaces" between inside and outside the body

34

Main two mechanisms of innate cellular immunity

1. inflammation
2. antiviral defense

35

Inflammation: how does it work

process of leukocyte recruitment and plasma proteins from the blood, their accumulation in tissues, and activation to destroy microbes

many activities involve cytokines produced by dendritic cells

36

Main cells involved in inflammation

leukocytes and plasma proteins

37

Innate immunity is the " ______" stage of immunity

decision making stage

it "evaluates" the invader in the context of intracellular vs extracellular microbes and then provides instructions to adaptive immunity

38

Cell communication is through

cell-to-cell signaling and cytokines and chemokines

39

Specific Signaling Receptors detect what?

specific cytokines

40

Functions of cytokines

growth, differentiation, activation of effector functions

chemokines assist in mobility of cells

41

T cells ---> ___ immunity?

cell-mediated (cellular immunity)

42

B cells ---? ____ immunity?

humoral

involves production of immunoglobulins

43

Cellular immunity:

a. who mediates it?
b. against what?
c. the function of CI
d. dual function

a. mediated by T-lymphocytes

b. fights intracellular infection

c. destruction of microbes residing in phagocytes, or killing of infected cells to eliminate them

d. assist B cells make effective antibodies

44

Humoral Immunity
a. who mediates it?
b. against what?
c. the function of HI
d. Details

a. Mediated by antibodies (Abs) in blood and mucosal secretions, produced by B lymphocyte

b. extracellular microbes

c. production of Abs to recognize, neutralize microbes, or target them for destruction by various effector mechanisms

d. Effector mechanism refers to the recruitment of cells that recognize antigens on microbes and destroy them

45

Immunopathology =

tissue damage caused by invasive microbes

46

Define antigens, and what do they include?

substances which induce an immune response

carbohydrates, proteins, lipids, and nucleic acids

47

The smallest unit to which an antibody can be made is

6 amino acids or 5-6 sugar residues

48

Describe the "smallest antigenic determinant"

6 amino acids or 5-6 sugar residues

49

The FULL name of the structure antibodies bind to

conformational antigenic determinant

50

conformational antigenic determinant relies on the

folding of the molecules

51

T cell receptors recognize

linear amino acid sequences

52

Ags which stimulate an immune response are called

immunogens

53

All _______ are antigens but not all _____ are ______

All immunogens are antigens but not all antigens are immunogens

54

Haptens

very small molecules that can bind to Abs and TCRs, but can't initiate an immune response

55

Innate immunity reacts to

products of microbes and injured cells

56

In humoral immunity ___ cells do what?

secrete antibodies that neutralize infection and eliminate extracellular microbes

57

In cell mediated immunity

T-helper cells activate macrophages to kill phagocytized microbes, or cytotoxic T lymphocytes directly destroy infected cells

58

Clonal Selection occurs how?

lymphocytes possessing specific Ag receptors bind to Ag, triggerign proliferation and differentiation, giving rise to clone cells speicific for Ag

59

Clone cells do what?

act in the presence of specific Ag to neutralize or eliminate Ag

60

"Ag-specific cells" late in the immune response, is responsible for what?

responsible for the 'memory' involved in adaptive immunity

61

B lymphocyte ---> 1 ---> 2 ---> outcomes

1. antigen recognition
2. differentiate into antibody secreting plasma cells
3. neutralization of microbe, phagocytosis, complement activation

62

Helper T Cell ---> 1 --> 2 --> outcomes

1. microbial antigen presented by antigen presenting cell to HTC

2. Helper T lymphocyte releases cytokines

3. cytokines can
a. activate macrophages
b. inflammation
c. activation (proliferation and differentiation) of T and B lymphocytes


63

Cytotoxic T lymphocyte (CTL) --> 1 ---> outcomes

1. infected cell expresses microbial antigen to CTL

2. CTL kills infected cell directly

64

Regulatory T lymphocyte --> 1 --> outcome

RTL suppresses other lymphocytes to reduce immune activity

65

the elimination of the antigen is called the

"effector stage"

66

Describe stage of antigen recognition to immune memory

4 parts

1. Antigen presenting cells interact with naive B and T lymphocytes,

2. B/T lymphocytes proliferate via clonal selection into
a. antibody producing plasma
cells
b. effector T cells

3. Contraction homeostasis
a. cells die by apoptosis

4. surviving cells are memory cells