Humoral Immunity

Humoral Immunity

1. Bacterial Defence

   • Inflammation
     • Innate immune
       • Adaptive
         • highly specific
         • Immunological Memory
         • Production of Antibody
           • same
             • On APC
             • Surface immunoglobulin
             • Antibody
               • attach to antigen
                 • Site: Epitope
                   • Linear: continuous
                   • Discontinuous

2. B cell development

   • Phase 1
     • Generation of B cells in bone marrow
   • Phase 2
     • Auto reactive cell eleminated in BM
       • B cell migrate to secondary lymphoid organs
         • Lymph nodes
         • Spleen
         • Payers Patches
         • Adenoid
         • Appendix
         • BALT
         • GALT
         • B cell trafficking
           • Inactivated
             • Afferent L.Vessel
               • T-cell area
                 • B-cell area
                   • Medullary cortex
                     • Efferent L.vessel
                 • via High Endothelial Venules
   • Phase 3
     • Activated B cell
       • Afferent L.vessels
         • T cell Area via HEV
           • B cell Area
             • Germination centre
             • Medullary cortex
               • Efferent L.vesels
                 • As Plasma cells
   • Phase 4
     • Antigen binding to B cell
       • Th2 cell deliver second signal via CD40
         • B-cell proliferate into plasma cell

3. antibody production

   • Antibody structure
     • Light chain
     • Heavy Chain
     • Segments
       • (V) Variable
       • (D) Diversity
         • heavy chain only
       • (J) Joining
       • (C) Constant
       • VDJ recombination
   • Antibody response Maturation
     • Affinity Maturation
       • production of antibody with increasing affinity towards antigen
     • Isotype switching
       • Change of antibody class
         • Acute
           • IgM
         • Overtime
           • IgG
       • Change in C gene
       • Require T cell help
       • enviroment affect class
       • Classes
         • IgG
           • Most abundant
         • IgM
           • Monomeric
             • Pentameric
         • IgD
         • IgA
           • Dimeric
         • IgE

4. antibody MOA

   • Neutralization
     • Toxin
       • block binding of toxin to receptor
     • Bacteria
       • block colonization & uptake
   • Complement activation
   • Opsonisation
     • phagocytosed mediated by Fc receptor
   • Antibody-directed cellular cytotoxicity
     • NK cell recognise Fc receptor on antibody bounded to pathogen
       • NK cell kill pathogen

5. Antibody fx

   • Serology testing
     • Dx potentitial infx agent
     • for fastidious org
     • mostly viruses
     • Measure IgG & IgM