Antibody and little description

1. NAME:-TALHA RASHID

4. CONTENTS:-
 Introduction
 Production
 Physical Occurrence
 Classes

5. INTRODUCTION;-
 An antibody , also known as an immunoglobulin (Ig),
is a large, Y-shape protein produced by plasma
cells that is used by the immune system to identify and
neutralize pathogens such as bacteria and viruses. The
antibody recognizes a unique molecule of the harmful
agent, called an antigen, via the variable region.
 Each tip of the "Y" of an antibody contains
a paratope that is specific for one particular epitope on
an antigen, allowing these two structures to bind
together with precision.
 The ability of an antibody to communicate with the other
components of the immune system is mediated via its
Fc region (located at the base of the "Y"), which
contains a conserved glycosylation site involved in these
interactions.The production of antibodies is the main
function of the humoral immune system.

6. ANTIBODY STRUCTURE;-
 An antibody molecule is composed of two identical Ig
heavy chains (H) and two identical light chains (L), each
with a variable region (V) & constant region (C).

7.  Antibodies Are Made Up Of:
 2 Light Chains (identical) ~25 KDa
 2 Heavy Chains (identical) ~50 KDa
 Each Light Chain Bound To Heavy Chain By
Disulfide (H-L)
 Heavy Chain Bound to Heavy Chain (H-H)
 First 100 a/a Of Amino Terminal Vary of Both H
and L Chain Are Variable
 Referred To As VL , VH, CH And CL
 CDR (Complementarity Determining Regions)
Are What Bind Ag
 Remaining Regions Are Very Similar Within
Same Class

8. STRUCTURE:-

9. PRODUCTION:-
 Antibodies are secreted by cells of the adaptive
immune system (B cells), and more specifically,
differentiated B cells called plasma cells.
 Made in response to exposure to the antigen.
Occurrence:-
Antibodies can occur in two physical forms, a
soluble form that is secreted from the cell, and
a membrane-bound form that is attached to the
surface of a B cell and is referred to as the B cell
receptor (BCR)

11. CLASSES:-
Five classes of Antibodies:
 IgG
 IgM
 IgA
 IgD
 IgE

12. IMMUNOGLOBULIN CLASSES
. IgG
 Structure: Monomer
 Percentage serum antibodies: 80%
 Location: Blood, lymph, intestine
 Half-life in serum: 23 days
 Complement Fixation: Yes
 Placental Transfer: Yes
 Known Functions: Enhances phagocytosis,
neutralizes toxins and viruses, protects fetus and
newborn

13. IgM
 Structure: Pentamer
 Percentage serum antibodies: 5-10%
 Location: Blood, lymph, B cell surface (monomer)
 Half-life in serum: 5 days
 Complement Fixation: Yes
 Placental Transfer: No
 Known Functions: First antibodies produced during
an infection. Effective against microbes and
agglutinating antigens.

14. IgA
 Structure: Dimer
 Percentage serum antibodies: 10-15%
 Location: Secretions (tears, saliva, intestine, milk),
blood and lymph.
 Half-life in serum: 6 days
 Complement Fixation: No
 Placental Transfer: No
 Known Functions: Localized protection of mucosal
surfaces. Provides immunity to infant digestive
tract.

15. IGA ANTIBODY TRANSPORT ACROSS CELL
(TRANSCYTOSIS):-

16. . IgD
 Structure: Monomer
 Percentage serum antibodies: 0.2%
 Location: B-cell surface, blood, and lymph
 Half-life in serum: 3 days
 Complement Fixation: No
 Placental Transfer: No
 Known Functions: In serum function is unknown.
On B cell surface, initiate immune response.

17. IgE
 Structure: Monomer
 Percentage serum antibodies: 0.002%
 Location: Bound to mast cells and basophils
throughout body. Blood.
 Half-life in serum: 2 days
 Complement Fixation: No
 Placental Transfer: No
 Known Functions: Allergic reactions. Possibly lysis
of worms.

18. CROSS-LINKAGE OF BOUND IGE
ANTIBODY WITH ALLERGEN CAUSES:-

19. MONOCLONAL ANTIBODIES;-
 Immunize Animal With Antigen
 Multiple Clones Are Generated, Good For In
Vivo
 For Clinical Diagnosis, Research, One
Clone That Reacts To Single Epitope Is
Preferred
 Solution By Kohler and Milstein
 Fuse A Myeloma Cell (Cancerous) With A
Normal Plasma Cells
 Resulting Clones Can Be Cultured Indefinitely
 Produces An Antibody Recognizing One Epitope

20. ANTIBODIES ACT AS IMMUNOGENS
 Antigenic Determinants on Abs Fall in 3 Categories
 Isotypic
 Allotypic
 Idiotypic
 Isotypic
 Constant Region Of Ab
 If you inject Ab in a different species Anti-Isotype is
generated
 If within same species, No Anti-isotype

21. ANTIBODIES ACT AS IMMUNOGENS:-
 Allotype
 Even though same isotypes within one species small
differences (1-4 a/a) arise in different individuals (form
of polymorphism)
 If injected with such Ab you generate anti-allotype Ab
 Ex. During pregnancy
 Blood transfusion

22.  Idiotype
 Unique VH AND VL binds antigen but can also
behave as antigenic determinant
 If you inject a monoclonal antibody into a
genetically identical recipient then anti-
idiotypic antibodies are generated
 No anti-isotypic and no anti-allotypic Abs will
be generated

23. MONOCLONAL ANTIBODY APPLICATIONS:-
 Diagnostic Tests
 Abs are capable to detect tiny amouns (pg/mL)
of molecules
 Ex. Pregnancy hormones
 Diagnostic Imaging
 mAbs that recognize tumor antigens are
radiolabeled with iodine I-131
 Immunotoxins
 mAbs conjugated with toxins