Immunity to Bacteria Flashcards
what are the clinical manifestations of TB?
infects macrophages in the lungs resulting in hypersensitivity response to form hard nodules called tubercles
how is TB treated?
with antibiotic Isoniazid
how are gram negative bacteria destroyed by the body?
lysis by complement and peptidoglycan degradation by lysozyme
what is the role of antibody in the response to bacteria
direct neutralization of toxins
secretory IgA on mucosal surfaces
binding of iron by lactoferrin (Required for bacterial growth)
how do macrophages and DCs recognise bacteria
pathogen recognition receptors
what are the pathogen recognition receptors for bacteria
mannosyl fucose receptors - sugars on surface
CD14 - removing microbes coated with LPS
Fc - antibodies bound to pathogen
complement receptors - complement coated microbes
what is produced in phagocytosis
reactive oxygen intermediates
- hydroxyl radical
- hydrogen peroxide
- nitric oxide
- superoxide anion
- hypochlorous acid
what are the evasion mechanisms of bacteria
anti chemotaxis factors capsules that inhibits phagocytosis inhibit phagosome/lysosome fusion catalase tough outer coat scavenges free radicals impaired MHC block IFNy effects
what is the evasion mechanism of strep pneumoniae?
capsule that inhibits phagocytosis
what are the evasion mechanisms of mycobacterium
blocks IFNy effects
impaired MHC
outer coat scavenges free radicals
what is the evasion mechanism of salmonella
impaired MHC
what are the complications of sepsis
circulatory collapse and DIC
vasodilation, drop in bp and shock
new therapy for sepsis
LPS removal - antiTNFa monoclonal antibodies
what is the immune response to fungi
neutrophils, macrophages and DCs
TLRs and Dectin 1
an example of respiratory fungi
histoplasmosis
