MIC 4124 Lecture Notes - Lecture 11: Eef2, Diphtheria Toxin, Antigenic Variation

• School: University of Ottawa
• Department: Microbiology and Immunology
• Course: MIC 4124
• Professor: L Isa D'ambrosio

Document Summary

Extracellular mechanisms: shielding or inhibition of pamps, antigenic variation, pneumoniae uses capsule to avoid phagocytosis and dehydration. Infection with one serotype will produce type specific immunity but it does not protect against a different serotype. Neisseria pili undergo dna recombination pils locus (no promotor) is silent and recombines with pile (promotor) to form variant: inhibition of opsonisation. Inactivation of enzymes of the complement cascade or block antibody binding to bacterium: inhibition or scavenging of ros, aureus expresses two superoxide dismutases to inactivate ros, resistance to antimicrobial peptides, block antibody mediated defense. Antibodies can neutralize, promote phagocytosis, or activate complement. Intracellular mechanisms: antigenic variation, inhibition of pamp signalling, pestis expresses yersinia outer proteins (yop) Yops can disrupt actin cytoskeleton and inhibit cytokine production: resistance to antimicrobial peptides, inhibition of phagosome and lysosome fusion, survival within phagolysosome, escape from phagosome. Listeria secretes llo to form pores of phagosome. Performs housekeeping functions to degrade damaged and dysfunctional organelles and proteins.