1. Immunology (elective) MLIM-101 Prepared by: Dr. Mohamed S. Abdel-Latif

2. Immunoglobulin: Isotypes, Allotypes and Idiotypes

3. Learning Outcome: At this time you should know the following: 1. To explain the structural basis for immunoglobulin isotypes, allotypes and idiotypes. 2. To describe some of the uses of isotypes, allotypes and idiotypes.

4. Immunoglobulin Isotypes Definition - Antigenic determinants that characterize the classes and subclasses of heavy chains and types and subtypes of light chains

5. Human IgM antiserum Reacts with IgM, IgG, IgA, IgD, IgE React with IgG, IgA, IgD and IgE Absorbed antiserum Reacts only with IgM Recognizes determinants specific for  heavy chains (isotypes) Immunoglobulin Isotypes ??

6. Immunoglobulin Isotypes Occurrence Importance –Ig levels –B cell tumors –Immunodeficiencies Definition Location IgM (kappa) IgG1 (kappa)

7. Immunoglobulin Allotypes Definition - Antigenic determinants specified by allelic forms of the Ig genes Location Occurrence – Source of anti- allotypic Abs IgG1 (kappa) Person 2 IgG1 (kappa) Person 1

8. Human Immunoglobulin Allotypes Nomenclature – G1m(3) – Km(1)

9. Human Immunoglobulin Allotypes Genetics (alleles) – Co-dominant autosomal genes Km(1)/Km(3) X Km(1)/Km(1) Km(1)/Km(1) and Km(1)/Km(3) – Allelic exclusion

10. Genetics (pseudoalleles) –Co-dominant G1m(17)G1m(1) 214355-358 Human Immunoglobulin Allotypes

11. Immunoglobulin Allotypes Definition Location Occurrence Importance –Monitoring bone marrow grafts –Forensic medicine –Paternity testing

12. Immunoglobulin Idiotypes Definition - Unique antigenic determinants present on individual antibody molecules or on molecules of identical specificity

13. DNP-BSA Strain A Mouse Anti-DNP Ab Purified anti-DNP Ab Strain A Mouse Ab against combining site of anti-DNP Ab ?? Immunoglobulin Idiotypes Antigenic determinants created by the HVR = Idiotypes

14. Immunoglobulin Idiotypes Definition Location IgG1 (kappa) Person 1 anti-B IgG1 (kappa) Person 1 anti-A

15. Immunoglobulin Idiotypes Definition Location Importance –V region marker –Regulation of immune responses

16. AgIdanti-Id + - anti-anti-Id + - Regulation by Id/anti-Id

17. Immunoglobulin Idiotypes Definition Location Importance –V region marker –Regulation of immune responses –Vaccines

18. AgIdanti-Id + - Anti-Idiotype Vaccines AgIdanti-Id +

19. Immunoglobulin Idiotypes Definition Location Importance –V region marker –Regulation of immune responses –Vaccines –Treatment of B cell tumors (T cell)

20. Assignment: As a part of the semester activity, group of students are selected every week to prepare a short seminar about his/her point of interest in one of the lecture topics. That to be discussed and evaluated during the next lecture.