introduction to antibody

1. GOVT.PG ART’S AND SCIENCE
COLLEGE RATLAM (M.P)
2018-2019
M.Sc 3rd SEMESTER
(MICROBIOLOGY)
PAPER – IMMUNOLOGY
TOPIC – IMMUNOGLOBULINS AND ANTIGEN –
ANTIBODY INTERACTION
SUBBMITTED TO : SUBBMITTED BY :
PREETI MA’AM MANORAMA CHOUDHARY

2. INDEX
IMMUNOGLOBULIN
• INTRODUCTION
• PROPERTIES
• GENERAL STRUCTURE
• FUNCTION
• CLASSES
• REFERENCE
ANTIGEN – ANTIBODY
INTERACTION
• INTRODUCTION
• CHARACTERISTICS
• DETECTION OF Ag- Ab
INTERATION

3. IMMUNOGLOBULIN

4. INTRODUCTION
• Immunoglobulins are Glycoproteins
formed in response to an antigen.
• They are found in the Serum, body fluid and
tissues.
• Produced by vertebrates.
“ All antibodies are immunoglobulin;
but all immunoglobulins may not be antibodies.”

5. PROPERTIES
• Ig are Glycoprotein.
• Definite sedimenation coefficient.
• Molecular weight ranges from 1,50,000 to
9,50,000.
• Contain disulfide bond.
• Half life varies from 2 to 25 days.

6. GENERAL STRUCTURE
• It is made up of 4
polypeptide chain.
• Consist of 2 heavy and 2
light chains.
• Structure divided into 2
region : Constant region
and Variable region.
and 2 Fragment : Fc
fragment and Fab
fragment.

7. FUNCTIONS
• Agglutination of antigen .
• Precipitation of antigen.
• Neutralization of antigen.
• Lysis of antigen.
• Tissue fixation.

8. PROPERTIES Ig G Ig A Ig M Ig D IgE
STRUCTURE
Monomer Dimer Pentamer Monomer Monomer
Heavy chain Gamma Alpha Mu Delta Epslion
No. of Ag
binding site
2 4 10 2 2
Molecular
weight
1,50,000 1,60,000 9,50,000 1,80,000 1,90,000
Serum
concentration
8 – 16 mg/ml 0.6 – 4.2
mg/ml
5 – 2 mg/ml 0.03 mg/ml 0.00004
mg/ml
Half life 25 days 6-8 days 5 days 2-3 days 2 – 3 days

9. PROPERTIES Ig g Ig A Ig M Ig D Ig E
Sedimentatio
n coefficient
7s 7s 19s 7s 8s
Carbohydrate
%
3 % 10 % 10- 12 % 12 % 12 %
Sub classes Ig G1 , Ig2 ,
IgG 3 , Ig G4
Ig A1, Ig A2 No sub
classes
Ig D1 , Ig D2 No sub
classes
Biological
function
cross
placenta ,
Participate In
secondry
immune
response
Presents in
colostrum.
Also provides
Immunity
against Tape
worms.
Detects –
congenital
syphilis,
rubella,
toxoplasmosis
Provide
antimicrobial
factor,
skin
sensitising
antibody,
Type I
hypersensitivi
ty
Characterstic
charater
Produce
particularly
during
Provide
mucosal
immunity.
Earliest Ig to
be
synthesized.
Extended hing
region
Without hing,
heat labile

10. ANTIGEN – ANTIBODY
INTRACTION

11. INTRODUCTION
• The interaction between
antigen and antibody is called
Antigen- Antibody Reaction.
• It is the basis of humoral
immunity or antibody
mediated immune response.
• They are used for detection of
disease causing agents and
some non- specific Ag like
enzyme.
• When Ag – Ab reaction
occures invitro they are known
as serological reaction.

12. CHARACTERISTICS
• Immune complex
• Specificity of Ag- Ab reaction
• Binding sites of antigen and antibody
• Binding forces of antigen and antibody
• Avidity
• Bonus effect
• Cross reaction

13. Immune complex
specificity
Binding sites

14. DETECTION OF Ag- Ab INTERACTION
• The process of antigen- antibody reaction cannot
be seen by the naked eye. But once the contact is
made, the ag-ab reaction leads to visible
manifestations such as :
1. Precipitation reaction
2. Agglutination reaction
3. Radioimmunoassay
4. ELISA
5. Complement fixation

15. PRECIPITATION REACTION
• Interaction between a
soluble antigen and its
antibody resulting in the
formation of insoluble
precipitate.
• Eg : reaction of
antibody with BSA

16. AGGLUTINATION REACTION
• The antibody of serum
causes the cellular
antigens to adhere to one
another to form clumps.
• When RBC are
agglutinated , reaction
called
Haemagglutination.
• Bacterial cell agglutinated
,reaction called Bacterial
agglutination.

17. RADIOIMMUNOASSAY
• A technique to test and
measure the
concentration of
antigen by making use
of radiolabelled antigen.
• Ist devised by Berson
and Yallow in 1959.
• For this discovery, they
were awarded the
Nobel prize In 1977.

18. ENZYME-LINKED IMMUNOSOBANT
ASSAY
• Technique used for
quantative determination of
concentrartion of certain
antigen or antibody.
• First introduced by Ingnal
and Perlman in 1970.
• Antibodies were absorbed
to a solid support a
polystyrene microtiter plate.
• Types :
1) Direct ELIAS.
2) Indirect ELIAS.
3) Competitive ELISA.

19. COMPLEMENT FIXATION
• The binding of
complement to antigen
–antibody complex is
called complement
fixation.
• When the antibodies
bind with the
pathogens, the antigen
– antibody complex
formed.

20. REFERENCE
• Dulsy fatima. N. Arumugam Saras Immunology
2016..Ed 5thSaras Publication..ch 8 pg. 163.
• Dulsy fatima. N. Arumugam.Saras Immunology2016..Ed
5thSaras Publication..ch14 pg.267.
• Kindt.Goldby.Osborne. Kuby Immunology 2007..Ed 6th
W.H.freeman and company.ch. 4pg..76.
• Kindt.Goldby.Osborne.. Kuby Immunology 2007..Ed 6th
W.H.freeman and company.ch. 6 pg. 145.
• Roitt,I. Essential Immunology 1997. Ed IX Blackwell
science Ltd. Australia. Ch.

21. Cont..
• http://www.slideshare.net/haddies/Antigen
antibody-reaction.
• http://fac-ksu.edu.sa/sites/…/immunology
leacture6 antigen-antibody-reactionppt..
• http://www.ncbi.n/m.nih.gov/pmc/articles/
pmc:2581910/life science events.com/online-
conferences/antibodies/

22. Cont..
• http://www.slideshare.net/immunoglobulin/
• http://www.thermofisher.com/in/en/.../
introduction immunoglobulins.html/
• http://www.sciencedirect.com/topics/
immunology-&-microbiology/immunoglobulin

23. THANK YOU