pathogens pathogens Neutrophils Eosinophils PMN/ Basophils - - PowerPoint PPT Presentation

Recognition of Recognition of extracellular extracellular pathogens pathogens

Neutrophils Eosinophils Basophils Mast cells Monocytes/ Macrophages Dendritic cells NK cells CD8+ Tc lymphocytes CD4+ Th lymphocytes B lymphocytes Myeloid Lymphoid PMN/ Granulocytes Mononuclear cells Innate Adaptive

PRR PRR PAMP PAMP eg. eg. macrophages macrophages

Production of acute phase proteins by the liver in response to interleukin-6 (IL-6) Liver

IL-6

C-reactive protein Mannan- binding lectin

Other acute phase proteins, eg: SAP SP-A SP-B Fibrinogen

Examples of Pattern Recognition Receptors (PRRs) expressed by macrophages

LPS receptor Mannose receptor Glucan receptor Scavenger receptor

Toll-like receptors (TLRs)

TLR6 TLR2 TLR2 TLR1 TLR4 TLR5 TLR3 TLR7 TLR8 TLR9 Peptidoglycans (Gram +) Lipoproteins Lipopolysaccharides GPI (T. cruzi) Zymosan (Yeast) Lipopolysaccharides (Gram -) Lipoteichoic acids (Gram +) RS virus F protein Flagellin dsRNA ssRNA G-rich

• ligonucs

Unmeth CpG DNA CD14

Plasma membrane Endosome

Antigen Antigen receptor receptor Antigen Antigen eg. eg. B lymphocytes B lymphocytes

Principles of vaccination illustrated by immunization with tetanus toxoid

Antibody response to tetanus toxin Time Immunization with tetanus toxoid Infection with tetanus bacterium Memory lymphocytes present Naïve lymphocytes present

Antigen combining site

Classes/isotypes: IgM; IgG (1, 2, 3, 4); IgA (1, 2); IgE; (IgD) Heavy chains: µ, γ, α, ε, δ Light chains: κ, λ Fab Fc

Heavy chain Light chain

VH

Cµ1 Cµ2 Cµ1 Cµ2 Cµ3 Cµ3 Cµ4 Cµ4 Cε1 Cε1 Cε2 Cε2 Cε3 Cε3 Cε4 Cε4

Class Switch

IgM IgE

Antibody isotypes: distribution IgM (pentamers) blood IgG (monomers) blood, tissues, placental transfer IgA blood/tissues (monomers) mucosal secretions and milk (dimers) IgE (monomers) tissues (bound to mast cells)