Test II Flashcards
Cells of the innate immune system and their functions
Neutrophil (phagocytosis), Macrophage (produce cytokines, phag, Ag present, in tissues), Dendritic cells (produce cytokines, phag, Ag present, in ECM), NK cells (produce cytokines, cytotoxic lymphocyte, lysis of viral infected cells, respond to tumor Ags)
Leukocyte Adhesion Deficiency (LAD)
innate immune cells cannot reach foreign antigens
Chronic Granulomatous Deficiency (CGD)
innate immune cells cannot kill foreign antigen
Pattern Recognition Receptors (PRR)s
Toll-like receptors (TLRs, on cell surfaces or in endosomes), NOD-like receptors (NLRs, intracellular/in cytoplasm), C-type lectin receptors (CLRs, funal antigens), RIG-I-like receptors (RLRs, cytoplasmic RNA helicases for anti-viral response), Mannose receptors (recognize bacteria and macrophages or dendritic cells with phagocytize)
Antibody in primary response, pentamer (10 binding sites), efficient, 5-10% of serum Ig - complement activation, agglutination, neutralization
IgM
Most abundant (80% of serum Ig), cross placenta - complement activation, agglutination, neutralization, opsonization
IgG
newborn immunity, predominant Ig class in external secretions (saliva, tears, breast milk, mucus-bronchial/GI/respiratory), 10-15% of serum Ig, monomer in serum, dimer in secretions - agglutination and neutralization
IgA
antibodies on mast cell surface - triggers release of histamines from basophils and mast cells - parasites and worm infections, allergic responses, mast cell sensitization
IgE
Ig involved in B cell maturation, found on B cells (along with IgM predominantly)
IgD
pseudomonas aeruginosa
opportunistic pathogen, life threatening for patients w/ CF - gram negative, rod shaped bacterium
C Diff
(clostridium difficile) - fills void from antibiotics, causes infection
Norwalk virus
fecal to oral transmission, problem with cruise ships, nursing homes, rehab centers (self-contained water systems)
bacteria in blood with clear rim around colonies
beta-hemolytic / Lancefield serum A
Group A Strepococci
G+ beta-hemolytic, produce M proteins & C5A peptidase - ex: Streptococcus pyogenes
can cause: pharyngitis, pneumonia, impetigo, cellulitis, otitis media, rheumatic fever, acute glomerulonephritis, toxic shock syndrome, meningitis
Actinomyces israelii
G+ rod, in GI and GU tracts, grows along tissue planes and can look like a mass
Bacteroides
G- pleo rod, anaerobe, non-spore, inhabit bowel and other GI sites
ruptured appendix –> peritonitis, inflammation (25% mortality); intra-abdominal and pelvic abscesses are 90% anaerobic peritoneal infections
Peptostreptococcus
G+, anaerobe, found in GI and respiratory tracts
can cause: abscesses, intra-abdominal sepsis, pleuropulmonary, pelvic and soft tissue infections, endocarditis, osteomyelitis, Polymicrobial infections (e.g., aerobic staphylococcus uses O2 so anaerobic peptostreptococcus survives too),
from human bites (normal flora)
Clostridium difficile
G+ rod, spore-forming, anaerobe, ubiquitous in nature and normal flora 2-5% of people (transient in others)
can overgrow after antibiotics (resistant) –> diarrhea, pseudomembranous colitis, toxic megacolon
spores = resistant to heat, dehydration, radiation, chemicals
Enterotoxin TcdA –> interferes w/ GTPases / actin organization, increased permeability of tight junctions
Cytotoxin TcdB –> increased vascular permeability / hemorrhage
blocks binding of complements to peptidoglycan layer, released by GASs, many serotypes (hard to get Abs for all of them)
M protein
C5A peptidase
blocks chemotactic signals of C5A peptide
Staphylococcus aureus
G+, coagulase (clots plasma - less phagocytosis), hyaluronidase (break down hyaluronic acid - more spreading), exotoxin (exfoliatin - causes skin peeling/exfoliation), leukocidin, hemolysin, protein A (binds Fc of IgG, rendering them useless)
can cause: bacteremia, skin infections, endocarditis; ultimately: SSSS (staph. scalded skin syndrome), TSST-1 (type of toxic shock syndrome), food poisoning (due to superantigen enterotxins)
normal or pathogenic flora
Neisseria meningitidis and Streptococcus pneumoniae
found normally in throats of 10% of people, pathogenic if displaced in their bodies or transferred to others
Neisseria meningitidis and Streptococcus pneumoniae
found normally in throats of 10% of people, pathogenic if displaced in their bodies or transferred to others
Streptococcus pneumoniae
G+
Mycobacterium
AFB (acid-fast bacteria)
E. coli
G- rods
