Lec 20- Adaptive Immunology

Question 1

Adaptive (specific) immunity

Answer 1

Is a specific attack against specific antigens by a small number of B cells and T cells that recognize very specific antigen determinants.

Question 2

Immunological competence

Answer 2

Ability to produce against non-self antigens while tolerating self-antigens. Occurs during first month of life.

Question 3

Autoantibodies

Answer 3

Exposure to such self-antigens results in production of autoantibodies.

Question 4

Autoreactive T cells

Answer 4

Killer T cells that attack self-antigens

Question 5

Clonal deletion theory

Answer 5

One of 2 mechanisms for tolerance.
Tolerance occurs because T cells that recognize self-antigens are destroyed.
Good evidence of this occurs in thymus.

Question 6

Clonal anergy

Answer 6

Lymphocytes dircted against self-antigens are present throughout life but don’t attack self-antigens.
Mechanism not understood.
Appears to underlie tolerance in B cells.

Question 7

Memory cells

Answer 7

When B cells divide, some progeny become memory cells.

Question 8

Plasma cells

Answer 8

A B cell that makes massive amounts of antibodies.
Some of those B cells division become plasma cells that produce about 2000 antibodies per sec that are specific for original antigen.
This provides active immunity.

Question 9

Primary response

Answer 9

On 1st exposure to pathogen, there is latency of 5-10 days before specific antibodies aee made.
Antibody level plateau after few days and decline after a few weeks.

Question 10

Secondary response

Answer 10

Subsequent exposure to same antigen caused secondary response.
Antibody production is much more rapid and sustained.

Question 11

Apoptosis

Answer 11

Programmed cell death.

Question 12

Active immunity

Answer 12

Development of a secondary response provides active immunity.
Involves activation of B cells.
Needs to be a min size requirement.

Question 13

Vaccination

Answer 13

Cause development of B cell clones that can provide secondary response.

Question 14

Passive immunity

Answer 14

A transfer of antibodies to a person.
I.e. by injection or in mother’s breast milk.
This provides and immediate response, because the persons B cells didn’t make the antibodies, it will only last a short time.
It will NOT prepare the body for a second attack.

Question 15

Ab/immunoglobins

Answer 15

Antibodies are proteins called immunoglobins. Part of gamma globulin class of plasma proteins.

Question 16

Heavy chain

Answer 16

Part of antibody structure (which is ‘Y’ shaped).

The ‘v’ part.

Question 17

Light chain

Answer 17

Part of antibody structure (which is ‘Y’ shaped).

The ‘l’ part.

Question 18

Fc fragment

Answer 18

When cleaved, the stalk of ‘Y’ becomes crystallizable fragment.
This is CONSTANT among different antibodies.

Question 19

Fab fragment

Answer 19

Arms of ‘Y’ contain antigen-binding fragment.

Contains a variable region that confers antibody specificity.

Question 20

Complement system

Answer 20

A collection of plasma proteins that are activated in cascade fashion on exposure to invading microorganisms, ultimately producing a membrane attack complex that destroys the invaders.

Question 21

Histocompatibility antigens

Answer 21

FIND

Question 22

HLA - human leukocyte antigens

Answer 22

A histocompatiblity antigen.

Are on surface of all body’s cells except mature RBC’s.

Question 23

MHC - Major histocompatibility complex

Answer 23

a group of genes that produce 2 different major plasma membrane proteins (class 1 and class 2).
Mark our cells as "self".

Question 24

MHC class I

Answer 24

molecules sample the proteins that are being synthesized inside the cell, and present the peptides to T cells to check to see that the cells have not been infected.

Question 25

MHC II

Answer 25

can present a foreign peptide to helper T cells to cause them to activate other cytotoxic T cells and B cells to the presence of a foreign pathogen.

Question 26

Coreceptors

Answer 26

FIND

Question 27

CD8/Cytotoxic or Killer T cells

Answer 27

Cytotoxic have CD8 on surface.
attack any cell wuth either the wrong MHC class 1 molecule or an MHC class 1 molecule with a foreign peptide on it.

Question 28

CD4/Helper T cells

Answer 28

Helper have CD4 on surface.
Helper T cells will recruit cytotoxic T cells and B cells and help to activate only those cells which will recognize their particular antigen.

Question 29

Virus

Answer 29

an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host.

Question 30

Autoimmune diseases

Answer 30

Are produced by failure of immune system to recognize and tolerate self-antigens.
Autoreactive T cells are formed and B cells produce autoantibodies.
Afflicts women twice as often as men.

Question 31

Immune complex diseases

Answer 31

Involve formation of immune complexes that are free and not attached to a cell.
These activate complement proteins and promote inflammation.
Can result form infection by bacteria, parasites, viruses.
Can result from formation of complexes between self-antigens and autoantibodies. This occurs in rheumatoid arthritis and systemic lupus erthematosis (SLE)

Question 32

Allergy/hyopersensitivity

Answer 32

Is abnormal immune response to allergens.

Question 33

Immediate

Answer 33

B ell. IgE. Antihistamine.
Is due to abnormal B cell response to allergen; causes effects in secs to mins.
Caused by foods, bee stings, pollen.
Treated with antihistamines.

Question 34

Delayed

Answer 34

T cell. Corticosteroids.
Is abnormal T cell response that causes symptoms 24-72 hours after exposure.
Treated with cortisol or its derivatives.