ADAPTIVE IMMUNE SYSTEM- OWN

Adaptive immune system ___________

is acquired

• doesn’t occur until pathogen is encountered

adaptive immunity is ______________

very specific

• immunity to one doesn’t confer immunity to another

adaptive immunity has a _______________

memory component

• it will produce a more effective response when a pathogen is encountered for the second time- faster and stronger.

The two components:

1. humoral immunity

2. cell mediated immunity

proteins that produce by the immune system that bind and inactivate foreign antigen________

antibodies

any foreign material that has the ability to activate the adaptive immune system is called___________

immunogens

the actual portion of the antigen that binds to the antibody is called ____________

Epitopes

• single antigen will have more than one epitope

immunogenicity

this increases the ability of an antigen to activate the immune system

each epitope

has a distinct antibody

hapten

low molecular weight compound that is too small on its own to activate the adaptive immunity

these are not immunogenic

bind to other molecules such as proteins in blood and tissue

wht are antibodies?

glycolysated protein molecules

what are antibodies also called

immunoglobulins

what are the four subunits of a protein molecule

1. two identical heavy chains

2. two identical light chains

what are the 3 distinct regions

2 identical variable region a.k.a fraction antibody (Fab)

1 constant region a.k.a fraction crystalise region (Fc)

Fab region

provides specificity of the antibody

Fc region

• allows for interaction with immune cells

• based on differences in Fc region

IgM

• pentameric

• always first Ab to be produced in response to an antigen

• on surface of B lymphocytes

• low affinity for antigen

• very good at agglutination

IgG

• monomer

• predominate Ab in the blood

• also in tissues

IgA

• dimeric

• secreted at mucosal sites

• defense against respiratory, reproductive, digestive tract information

IgD

• monomer

• surface of B cells

• activate B cells to produce Ab against a specific antigen

IgE

• monomer

• binds to receptor on mast cells and basophils

• triggers degranulation and histamine release

• allergy

neutralization

• Ab binds to antigen blocking attachment sites

opsonization

• Ab coats the surface of the bacterial cell

• attracts phagocytes

• enhances rate of phagocytosis

• phagocyte- ability to interact w/Fc region of the Ab

agglutination

• clumps many antigens together

• phagocytosis occurs more effeciently

antibody mediated cytotoxicity

• attachment of antibody to parasites recruits eosinophils

• eosinophils attach to Fc componenet of Ab

• activated eosinophils release reactive oxygen sp. and hydrolytic enzymes

• parasite is dead

complement activation

• system consisiting of a series of proteins found in the blood

• creates Membrane Attack Complex

MAC (Membrane Attack Complex)

• goes into bacteria and creates a pore in the wall

• cell contents leak out and bacterium dies

B cells are __________ cells

antigen

All antigen presenting cells can insert ______ into the plasma membrane

MHC II

What is MHC II

Major Histocompatability Complex

Ab is produced against __________

exogenus antigen

what is the first step in Ab production

B cell phagocytoses exogenous antigen

What happens to the digested content in the phagolysosome during antibody production?

It will be complexed together with MHC II and inserted into the extracellular fluid

How is the digested content from the phagolysosome in antibody production different from other phagocytosed material?

It will not be exocytosed to the extracellular fluid

role of T helper cells in Ab production

T helper cells bind to MHC II-Antigen complex, resulting in T helper cell activation.

How do activated T helper cells contribute to antibody production?

The activated T helper cell releases cytokines that bind to receptors on the B cell, resulting in B cell proliferation.

What is the significance of MHC II-Antigen complex in antibody production?

The binding of T helper cells to MHC II-Antigen complex leads to T helper cell activation in the process of antibody production.

What will some of the newly produced B cells become?

plasma cells

What do plasma cells do?

Actively transcribe, translate, and secrete an identical antibody protein to the extracellular fluid.

What are the antibodies produced by plasma cells specific to?

The original exogenous antigen.

What is the primary antibody response?

Occurs the very first time a specific antigen is encountered

What is the secondary antibody response?

Occurs every additional time (after the primary response) a specific antigen is encountered

What is the major goal of the primary antibody response?

Results in the production of memory B cells

what is the difference between 1^o Ab response and a 2^o Ab response

primary is slow, secondary is fast

what is tolerance

this prevents the immune response against self-antigens

tolerance helps to prevent ______

auto-immune disease

what does cell- mediated immunity do

it recognizes and destroys abnormal cells present in the body

what are endogenous antigen

present inside of the host cell

What type of cells are involved in recognizing and destroying abnormal cells present in the body?

Cytotoxic T cells

What type of antigen is present inside of the host cell and displayed in the plasma membrane complexed with MHC I?

Endogenous antigen

What is released by cytotoxic T cells to cause death of the infected host cell?

Perforins and granzymes - these casue the death of the infected host cell