2. Adaptive immune response: structure of the antigens and immunoglobulins

Question 1

what are the 2 major forms of specific (acquired) immune response

Answer 1

are the humoral and cellular immunity

Question 2

what is active immunity

Answer 2

the immune system of the individual actively responds to the antigen.

Question 3

what is passive immunity.

Answer 3

An individual may specifically be made immune by recieving the cells or immunglobulins of an already immunized individual.

Question 4

what is an antigen

Answer 4

antigen is a substance, which is recognized by T cell and/or B cell receptors, and it is able to induce active immune response or tolerance according to the host MHC haplotype

Question 5

Antigen: precise specificity is present since

Answer 5

on the surface of the B- and T-lymphocytes there are membrane receptors that can recognize tiny differences in the structure of antigens.

Question 6

what is an antigen made of

Answer 6

It is usually a protein with large molecular weight (polysaccharide etc.).

Question 7

what part of the antigen take part of the binding of the antibody produced against it

Answer 7

epitop

Question 8

how do antigens develop

Answer 8

Antigen specific lymphocytes develop without any antigen stimulus

Question 9

Antigen classification

Answer 9

antigenicity

Question 10

Antigen classification

Answer 10

immunogenicity

Question 11

Antigen classification: Antigenicity what is it

Answer 11

auto-antigens (self matter)
allo- antigens (matter of the same species)
xeno- antigens (matter of different species)

Question 12

Antigen classification: Antigenicity determined by what

Answer 12

epitop

Question 13

Antigen classification: Antigenicity binding force

Answer 13

Affinity (one epitop) = antigen-antibody
complex concentration multiplied by the product of the free antigen and the free antibody

Question 14

Antigen classification: specificity

Answer 14

means the the antibody is specialised to bind one well defined chemical structure. the antibody can often be so specific that it can differentiate one stereoisomer of the antigen from another

Question 15

Antigen classification: immunogencity what is it

Answer 15

the antigen can react with the antibody produced against it

Question 16

Antigen classification: immunogencity how do you grade them

Answer 16

foreigness
molecular weight

Question 17

Antigen classification: immunogencity foreigness

Answer 17

Autoantigen ● Alloantigen ● Xenoantigen

Question 18

Antigen classification: immunogencity weight

Answer 18

Under 4000 – weak
● Over 100 000 - strong

Question 19

Immunoglobulins what is it

Answer 19

Large glycoproteins that are secreted by plasma cells and that function as antibodies in the immune response by binding with specific antigens.

Question 20

Immunoglobulins production step 1

Answer 20

Synthesized by plasma cells (which are differentiated from B-lymphocytes)

Question 21

Immunoglobulins production step 2

Answer 21

During humoral immune response a selected antigen specifically activates the B-cells, which will produce the immunoglobulins.

Question 22

Immunoglobulins production step 3

Answer 22

B-lymphocytes both recognize and produce antibodies in the different phases of their maturation.

Question 23

Immunoglobulins production step 4

Answer 23

B-lymphocytes with cell surface immunoglobulins are also called the “recognizing cells” in the humoral immune response as they specifically bind to a given antigen. Antigen binding triggers the cell differentiation which leads to the transformation of the B-lymphocyte into plasma cells secreting antibodies

Question 24

Structure of antibodies:

Answer 24

FAB (fragment antigen binding)
FC (fraction crystallisable)
Variable region
Joint region (hinge)
H-chains (heavy chains): two
- L-chains (light chains):two
Amino acids in the
variable (V) domain.
- Constant (C)

Question 25

Structure of antibodies:FAB

Answer 25

The part that is responsible for
binding the
antigen.

Question 26

Structure of antibodies: FC

Answer 26

The part that is
responsible for the biological effect.

Question 27

Structure of antibodies: variable region

Answer 27

Two hypervariable antigen binding sites. Each of these pairs of subunits binds one antigen.

Question 28

Structure of antibodies: Joint region (hinge)

Answer 28

Makes the molecule more
flexible while binding the antigen.
Disulfide bond.

Question 29

Structure of antibodies:Constant (C)

Answer 29

chains have constant amino acid components.