Antibody Production March 2005 Modified 2008 Type I

Antibody Production March 2005 – Modified 2008 Type I Hypersensitivity Dr. Khaled S. Tabbara Presenter: Abdullah

The Immune Response Innate Immunity Acquired Immunity Phagocytes Complement Natural Killer Cells B Lymphocytes Antibodies T Lymphocytes Cytotoxic T Lymph. Help / regulatory T lymphocytes

The Acquired Immune Response Lymphocytes B Lymphocytes T Lymphocytes CD 4+ T Helper Th 1 Cell-Mediated Responses CD 8+ Cytotoxic Th 2 Antibody Responses

Immune Responses Beneficial Responses Defense Protection Detrimental / Harming Responses Allergy (Hypersensitivity) Autoimmunity

B Lymphocyte Clonal Selection

Antibody Production

Roles of Th 1 and Th 2 cells in the Immune Response Helper T cells

Th 1 Th 2 IL-2, IFN , TNF IL-4, IL-5, IL-6, IL 10 Responses to intracellular parasites Delayed Type Hypersensitivity Responses to helminths & Allergens Immediate Type Hypersensitivity

Type I Hypersensitivity ( = Immediate Type Hypersensitivity )

Four Types of Hypersensitivity Reactions

Induction of Atopy IL-4 Naïve Th IL-4 / IL-13 Th 2 IL-4 Positive feedback B lymphocyte IL-5 / IL-13 Ig. E Eosinophilia

Type I Hypersensitivity • Ig. E Antibodies • Mast Cells

Type I Hypersensitivity Ig. E Binding to high-affinity Fc Receptors for Ig. E (Fc RI) on surface of Mast cell (Mast cell SENSITIZATION) Antigen Cross-linkage of Ig. E on surface of Mast cells Release of Mediators from Mast cell Granules Synthesis of “Late” mediators

Role of Eosinophils in Allergic Asthma Release of: • Major Basic Protein (MBP) • Eos-derived neurotoxin • Peroxidase • Cationic protein Effects of MBP • Damage epithelium • MC degranulation • Basophil degranulation