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Flashcards in Acquired Immunity Deck (24):
1

Differences between innate and acquired immunity? Similarities?

Innate:

-rapid response (hours)

-fixed, broad

-limited number of specificities

-constant during response

 

Acquired:

-slow response (days to weeks)

-variable

-highly selective specificities

-improve during response

-memory

-more advanced

-resolves infection usually

Similar -common effector mechanisms for destruction of pathogens

2

Besides infectious processes, what is the immune system involved in?

-transplantation immunity

-autoimmune disorders

-hypersensitivity (allergies)

-tumors?

3

What is the immune system composed of?

cells:

-lymphocytes

-granulocytes

-macrophages, monocytes, dendritic cells

 

Molecules:

-antibodies

-cytokines

-complement

4

What are the lymphoid cells? where are they produced? Function?

B lymphocytes:

-made in bone marrow

-key in adaptive immunity (humoral)

 

T lymphocytes:

-made in thymus

-key in adaptive immunity (humoral and cell mediated)

5

Describe the antigen receptors on B lymphocytes?

-have an antigen binding site-determines which cell responds, very specific

-heterodimer chain

-light chain with binding site

-heavy chain which anchors molecule, goes through transmembrane region

-more diverse

6

Describe antigen receptors on T lymphocytes?

-antigen binding site, very specific

-alpha and beta chain

-variable region on top

-constant region on bottom

-anchored in transmembrane region

-less diverse, recognize linear molecules

7

Explain why B and T lymphocytes are important to adaptive immunity?

T -centrally important in most adaptive antigen specific immune responses

-made in thymus

 

B -make antibodies which can attack viruses or bacteria

8

What are antibodies? Where are they produced? Function? What do they look like?

-protein that binds specifically to an antigen

-produced by plasma cells (differentiated B cell) in response to infection or immunization

-binds to and neutralizes pathogen or prepares for destruction by phagocytes or complement

-look like B lymphocytes, but chains are connected by disulfide bonds

9

What are the major subsets of T cells? What do they regulate? Functions?

CD4+:

-helper/inducer

-make cytokines

-regulate afferent (generation) and efferent (effecting the response) arms of many different types of response

-produce antibodies

-generate cell mediated and humoral responses

-Regulatory T cells

 

CD8+:

-cytolytic T cells

-cytotoxic or cytolytic for cells bearing relevant antigen

-regulates immune responses (suppression)

10

Functions of B lymphocyte, Helper T lymphocytes, Cytotoxic T lymphocytes, Regulatory T lymphocytes?

B -make antibodies

-neutralize microbes, phagocytosis, complement activation

 

Helper T -make cytokines

-activate macrophages

-inflammation

-activation of T and B lymph

 

Cytotoxic T -kill infected cells

 

Regulatory T -Suppress other lymphocytes

11

What are the types of specific immunity? Specificity? Memory?

Active:

-generate a response

-natural via infection

-artificial via vaccination

-specific

-has memory

 

Passive

-natural by transplacental or colostral transfer of antibody

-artificial by administration of immune globulins

-specific

-no memory

 

Adoptive -transfer of immune cells

12

What activates natural killer cells (NK)?

when a virus inhibits class 1 MHC expression

13

What are natural killer cells? Function?

-clear virally infected cells

-clear tumor cells

-effector in natural immunity

-act in same time frame as innate

-faster than B and T cells

-may enhance inflammation

-phagocytosis of extracellular microorganisms and viruses

14

What are the two subsets of NK cells? Function? Where found?

CD56 dim -make up 90% of NK cells in blood

-enhanced cell killing capacity

 

CD56 bright -make up 90% of NK cells in tissues

-enhanced growth factor and non inflammatory cytokines

15

What leukocytes have the biggest proportion in human blood?

-neutrophil (40-75%)

-lymphocyte (20-50%)

16

What are the cardinal features of adaptive immune response?

-specifity

-diversity

-adaptibility

-memory

-self limitation

-discrimination of self and non self

17

Cardinal features: specificity?

-an immune response is specific for distinct antigens

-function of distinct antigen receptors on the lymphocyte surface

-antigen receptors present before exposure to antigen

-basis of clonal selection theory

18

Cardinal features: diversity?

-total number of antigenic specificities of lymphocytes in an individual is large

-individual can discriminate at least 1 billion different antigens

-result of incredible variability in the antigen receptors among lymphocytes

19

Cardinal features: adaptability?

ability to respond to antigens not previously encountered in nature

20

Cardinal features: memory?

-exposure of the immune system to foreign antigen enhances its ability to respond again

-secondary immune responses are more rapid, bigger, qualitatively different

21

Cardinal features: self limitation?

-immune response wanes with time because of the elimination of antigen, effector cells are short lived, regulatory feedback elements of immune response

22

Clonal selection theory?

-every individual contains numerous clonally derived lymphocytes

-each lymphocyte has an antigen receptor specific for a single antigen

-these are present prior to exposure to antigen

-antigen selects a pre existing clone and activates it

23

What is the architecture of a lymph node? where do T cells and B cells congregate?

T cells- in center

B cells- outer

24

What is the difference between the primary and secondary immune response to the same antigen?

see pic