nature of antigen and antibodies

what is the other name of antigens

immunogen

a foreign substances usually protein and

polysaccharide

antigen

this Triggers a specific immune response and induces

the formation of a specific antibody or T cells

response or both.

antigen

what subtance does an antigen combine to

antibody

this is the antigenic determinant

epitope

this is the site which are recognized by T cells or

B cell

deteminant site

epitopes bind to?

T cell receptor and antibodies

this is a region of an antigen that binds to

antigen-specific receptors on lymphocytes or to

secrted antibodies

active region

The ability of antigen to react specifically with a free Ab or membrane coupled antibody (BCR)

antigenicity

The ability to induce a humoral or cell mediated immune response.

immunogenicity

specific protein that is produced in response to an immunogen and reacts with an antigen

antibody

A substance that is non-immunogenic But it can react with the products of a specific immune response with no Antibodies formation

Hapten

what is the moleculr weight of a hapten

less than 10000

Has the property of antigenicity but not immunogenicity

hapten

what are thefactors affecting immunogenecity

foreignness , size, chemical composition and complexity, route dosage and timing, adjuvants

-the more different the composition, the greater the response

foreignness

derived from the same individual

autoantigen

derived from the same species

alloantigen

derived from the different species

heteroantigen

ag found in unrelated plants and animals, crossreact with Ab of another

heterophile antigens

what are the different type of antigens according to their foreignness

autoantigen, alloantigen, heteroantigen, heterophile antigen

the larger the molecule the more immunogenic

size

how many daltons of ag is considered to be a potent antigen

greater than 10000 daltons

givean exmple of a good immunogen and give the corresponding daltons

abumin 40000 daltons

give an example of an excellent immunogen and their corresponding daltons

hemocyannin 1 million daltons

the more complex an antigen the more immune response is in acted

chemical composition and complexity

what is the most immunogenic

protein derived antigens

what is the 2nd most immunogenic

polysaccharide derived antigen

what are the non immunogenic

lipids and nucleic acid derived antigens

what is the most effective route for antigens

intravenous and intraperitoneal

which would be a stronge stimulus intradermal or intramascular

intradermal

the smaller the dose _______________

the less the response

what are the different routes

oral, intramascular, intradermal, intravenous

howlong does intradermal takes before the body reacts

30 minutes

Substance added to vaccine and less immunogenic molecules (Hapten) to increase the immune response

adjuvants

what are the different functions of an adjuvant

stimulates T-cells, B cells, and phagocytosis

give examples of adjuvants

Complete Freund’s Adjuvant, lipopolysaccharide, alum adjuvant, and squalene

what is the adjuvant used for HIV

squalene

what are the 2 type of antigens

T-independent antigen and T-dependent antigen

antigens which can directly stimulate the B cells to produce antibody without the requirement for T cell help In general.

T-independent antigen

give examples of T-independent antigens

pneumococcal polysaccharid, lipopolysaccharide,flagella

those that do not directl stimulate the production of antibody without the help of T cells.

T-dependent antigen

which type of antigen is more dangerous to the human body

T-dependent antigen

Glycoproteins that recognize and bind to a particular antigen with very high specificity.

antibodies

what is antibodies prmarily composed of

glycoprotein

how many epitopes does an antibody have

at least two identical sites

what group of serum proteins does antibodies belong to

immunoglobulins

in electropheresis what is the pH used

8.6

at what band does immunoglobulin primarily appear

gamma band

funtions of immuno globulin

Neutralization, facilitate phagcytosis, combine with antigen

give the different Theories of Antibody

Diversity

Ehrlich’s side chain theory, template theory, and clonal selection

this theory states that certain cells had specific surface receptors for antigen

Ehrlich’s side chain theory

who theororized the template theory

Felix Haurowitz

what theory states that a specific antibody enters the circulation, while the antigen remains behind to direct further synthesis

template theory

independently supported the idea of clonal selection process for antibody formation.

Niels Jerne and Macfarlane Burnet

individual lymphocytes are genetically programmed to produce one type of immunoglobulin and that a specific antigen finds or selects those particular cells capable of responding t it, causing to proliferate

clonal selection theory

A flexible Y-shaped molecule with four protein chains:

Monomer

Two sections at the end of Y’s arms. antigen binding sites (Fab) Identical on the same antibody, but vary from one antibody to another.

Variable regions

Stem of monomer and lower parts of Y arms.

Consant region

For Complement fixation, Skin Fixation and Placental transfer

Fc region

this part of the antibody dectates what type of immunoglobulin it will be

Heavy chain

refers to the heavy chain that determine the Ig class

Isotype

Minor variations of in the constant region

allotype

Variations in variable regions

idiotype

Possess both constant and variable regions

light chain

this is the varriable part of the light chains

lambda

this is the constant part of the ight chain

kappa

Connect heavy chains and heavy chains. Connect heavy and light chains. Connect light chains and light chains

Disulfide bonds

the flexible region which is found between CH1 and CH2

Hinge region

Regions or sections in an Ig molecule

domain

how many domains does a light chain have

2

what are the domains od a heavy chain

VH, CH1,CH2,CH3

what Ig has an extra CH4

IgM and IgE

cleaves the Ig above the hinge region

papain digestion

-cleaves Ig below the hinge region

pepsin digestion

what are the subclasses of IgG

IgG1,IgG2,IgG3,IgG4

what is the serum concentration of IgG

800-1600

what is the serum half life of IgG

23 days

what is the predominant IgG subclass

IgG1

how is. its subclasses differentiated

the number of ther disulfide bonds

what is the best IgG for complement fixation

IgG3

which IgG is most efficient in providing immunity to newborn

IgG1

what is the appearance of IgM in its free state

star-like appearance

appearance of IgM combined with Ag

Crab-like

known as the macroglobulin

IgM

•First to appear in ________ and the last to leave in senescence

phylogeny

IgM is Formed in response to stimulus by _______________

gram negative bacteria

this is the best agglunin

IgM

Most efficient in triggering the classical complement pathway

IgM

what are the subclasses of IgA

IgA1 and IgA2

IgA in serum

IgA1

IgA in secretion

IgA2

the Secretory Component of IgA provides

Mucosal Immunity

-Prevents attachment of pathogen to mucosal surface

mucosal immunity

responsible for immunoregulation

IgD

Least abundant Ig in serum

IgE

IgE Heat labile antibodies where originally called

reagin antibody

IgG mediates hypersensitivity reactions such as

allergies and anaphylaxis