This document discusses the structure, properties, genetic organization, and genetic rearrangement of antibodies which allows for antibody diversity. It notes that antibodies are glycoproteins produced by plasma cells that recognize and bind antigens. Their genetic organization involves genes for heavy and light chains being located on different chromosomes, with multiple gene segments that undergo rearrangement. This rearrangement at the DNA and RNA level involves joining of V, D, and J genes for heavy chains and V and J genes for light chains, and splicing with C region genes to produce different antibody classes. This genetic rearrangement and splicing is essential for producing the antibody diversity needed to recognize a wide range of antigens.

1. CHAITRALI. VIVEK. JADHAV
ROLL NO:- 07
PAPER:- 2

2. OBJECTIVES:
 Antibody- structure and properties
 Genetic organisation
 Genetic rearrangement
 Antibody diversity

3.  Glycoprotein.
Produced by plasma cells.
Recognize & bind antigens.
Leads to:
 Phagocytosis
 Complement activation
 Antibody dependent cell cytotoxicity (ADCC).

5.  Opsonization.
 Immune Adherence.
 Transcytosis.
 Complement Activation.
 Virus and Toxin Neutralization.
 Antibody-Mediated Cellular Cytotoxicity.
 Direct lysis of Microbes.

6.  Located on different chromosomes for different chains:
 H-chain gene family on Ch 14.
 Kappa light chain gene family on Ch 2.
 Lambda light chain gene family on Ch 22.
One family multiple gene segments for variable
region.
One gene segment multiple genes for same
specific region.

7.  Encoded by 3 genes:
 V (variable gene)
 J (joining gene)
 C (constant gene)
V & J together code for variable region ( VL).
C gene codes for the constant region ( CL).
A complete L chain formed by splicing of V, J & C
genes.

9. Encoded by 4 genes:
 Variable region coded by 3 genes:
VH (variable)
JH (joining)
DH (diversity)
Constant region (CH) encoded by one single
gene.
H-chain C-segment has 9 genes.

11.  One that occurs at DNA level.
 Another that occurs at RNA level.

12. V,D & J joining in H-chains; V & J joining in L-chains.
C region genes remain separated from V-region gene
by J genes and intron.
A primary RNA transcript is generated.
Only Cμ & Cδ genes are transcribed in naïve B cells.
The other C region genes transcribed during class
switching.

13. Takes place during the primary RNA transcript
processing.
The C-region gene spliced with V-region genes to
generate complete H & L chain genes.
Plays crucial role in:
 Production of membrane bound Ab.
 Production of secreted form of Ab.
 Production of different classes of Ab.

14. Rearranged V region at DNA level contains the
following sequences from 5’ end to 3’ end:
 L-exon of joined VH gene.
 VHDHJH –combined exon.
 Intron between L & VHDHJH.
 Intron 3’ to J gene.
 Remaining JH genes, if any, followed by complete set of CH
region genes.

15. The rearranged H-gene is transcribed.
Next rearrangement at RNA level takes place.
Differential splicing of the primary RNA transcript
leads to generation of mRNA for both μ and δ
heavy chains.
After translational, leader peptide is cleaved to
produce a fully functional chain.

17.  Occurs after the rearrangement in heavy chain.
Similar in pattern.
No D-genes involved.
Variable region rearrangement in DNA.
Splicing with C-region gene during RNA
processing.

20.  Immunology, 5th edition, by kuby.
 Textbook of basic and clinical immunology – by Sudha
Gangal & Shubhangi Sontakke.
 www.slideshare.com
 https://www.youtube.com/watch?v=chwXp564-6o