2. The second line of defense via recognition of common bacterial components Innate Immunity provide the second line of defense against pathogens Not pathogen-specific and do not improve with repeated exposures to antigen(no memory) Lack diversity generated by recombination
2. The second line of defense via recognition of common bacterial components • Innate Immunity provide the second line of defense against pathogens • Not pathogen-specific and do not improve with repeated exposures to antigen (no memory) • Lack diversity generated by recombination
Innate immune recognition of bacterial cell wall components rin lipopolysaccharide teichoic acid outer membrane peptidoglycan lipoteichoic acid plasma membrane plasma membran Gram-negative bacteria Gram-positive bacteria @2004 New Science Press ltd
Innate immune recognition of bacterial cell wall components Gram-negative bacteria Gram-positive bacteria
Gram negative bacterium 0000000002 000000000 LBP LBP-LPs lipoprotein flagellin Cellular location of CD14 CD36 TLRs on host cell exterior TLR4/MD-2 TLR2/TLR6 vIrion CpGDNA TLRs that recognize viral RNA nucleic acids are TLR7 ds RNA localized inside cells TLR9 phagolysosome C2004 New Science Press Ltd or endosome TLR3
Cellular location of TLRs on host cell TLRs that recognize nucleic acids are localized inside cells
Phagocytosis binding of particle soluble opsonins to particle o neutrophil secondary lysosome granule granules internalization particle binding via phagocytic。 receptor fusion of phagosome with primary, secondary granules and phagolysosome particle engulfment with actin C New Science press ltd 2004
Phagocytosis © New Science Press Ltd. 2004
Phagocytosis and killing fusion of phagosome with primary, secondary granules and phagolysosome lysosomes Primary granules: Secondary granules Antimicrobial peptides phagocyte oxidase isozyme (degrades peptidoglycan) Lysosomes: Proteases(elastase, etc. Digestive enzymes C New Science press ltd. 2004
Phagocytosis and killing Primary granules: Antimicrobial peptides Lysozyme (degrades peptidoglycan) Proteases (elastase,etc.) Secondary granules: phagocyte oxidase Lysosomes: Digestive enzymes © New Science Press Ltd. 2004