Flashcards in EXAM #1: REVIEW Deck (47)
What are the three major components of the innate immune system that defend against viral infection??
1) Type I IFN (alpha and beta IFN)
2) NK Cells
What is the general mechanism by which NK cells kill virally infected cells?
Perforin and granzyme, which induce apoptosis
What are the two ways that NK cells are induced to kill virally infected cells?
1) PAMPs and/or absence of MHC Class I
- IgG is bound to virally infected cell
- CD16 of NK cells binds Fc portion of antibody
*Perforin and granzyme are released, triggering apoptosis
What cytokines/ cellular product mediate the anti-viral effects of macrophages?
List five functions of antibodies in an anti-viral response.
1) Prevention of viral binding to target cell
3) Complement activation
4) NK cell activation/ ADCC
5) Downregulation of viral gene expression
What innate immunity cells predominate in the response against intracellular bacteria?
2) NK cells
Outline how macrophages and NK cells are activated to produced an anti-bacterial (intracellular) response?
1) Macrphages activated to release IL-12
2) IL-12 activates NK cells
3) NK cells release IFN-gamma (Type II IFN)
4) IFN-gamma further activates macrophages
5) Macrophages release NO, which is a potent antibacterial measure
What is the adaptive immune response to intracellular bacteria?
T-cells are activated to produce IFN-gamma, which activates macrophages
List the major complications of acute otitis media.
1) TM rupture
5) Lateral sinus thrombosis
6) Meningitis/ brain abscess
How acute bacterial sinusitis treated?
2) Nasal decongestants
What are the major complications of acute bacterial sinusitis?
2) Cavernous sinus thrombosis
3) Boney invasion of the orbit
What is the hemolysis pattern of S. pyogenes?
What complement pathway is specifically inhibited by polysaccharide capsules?
How does S. pyogenes evade the immune system?
- Produces M protein
- M protein prevents complement activation
How does S. pneumoniae evade the immune system?
What is the major mechanism of immunity against spirochetes?
What is the major role of cell-mediated immunity (Th1) in spirochete infections?
Clearing the infection
*Vs. Th2 that prevents reinfection
What cell type mediates the innate immune response against fungal infections?
*Partly why neutropenic patients are so susceptible to C. albicans
What is the major adaptive immune mechanism against fungal infections?
Cell mediated immunity (Th1)
What is the major immune mechanism against Plasmodium? What stage of infection is being targeted?
Th1 vs. the intrahepatic stage
List four ways that parasites evade the immune system.
1) Conceal in gut lumen
2) Coat with host proteins
3) Produce enzymes that cleave bound antibodies
4) Inhibition of complement activation*
List the four major organisms that cause infectious diarrhea.
1) E. coli
4) C. diff
How is H. pylori treated?
1) PPI + amoxicillin
2) PPI + clarithromycin + tinidazole
What is quadruple therapy for h. pylori?
1) Bismuth subsalicylate
Why is duration of diarrhea an important historical feature to ask about?
Less than 2 weeks= infectious
More than 2 weeks= not infectious
What are the two major non-inflammatory diarrheas?
1) V. cholerae
What is the empiric treatment for chlamydia?
What are the non-infectious etiologies of a presentation similar to a CNS infection?
2) Collagen vascular disorder
What are the expected CSF findings in bacterial meningitis?
- WBC: 1,000 - 5,000 (highest)
- Protein: 100- 500
- Glucose less than 40