First Aid, Chapter 1 Immune Mechanisms, Innate Immunity and Toll-Like Receptors Flashcards
What are the innate mechanisms used on extracellular bacteria?
Complement activation Phagocytosis: Recognition by pattern recognition receptors (PRR)
What are the innate mechanisms used on intracellular bacteria?
Nucleotide binding oligomerization domain-like receptors (NLRs)
What are the innate mechanisms used on fungi?
Neutrophil phagocytosis Complement activation
What are the innate mechanisms used on viruses?
Phagocytosis: Toll-like receptors (TLRs) and NK cells
What are the innate mechanisms used on parasites?
Phagocytosis; Complement (alternative pathway)
What is the difference in the genetics of innate immunity vs. adaptive immunity?
Innate immunity: Response encoded in host germ line DNA
Adaptive immunity: somatic gene rearrangement
What does the innate immune system recognize in pathogens?
Recognize conserved sequences such as pathogen-associated molecular patterns (PAMPs)
What does the adaptive immune system recognize in pathogens?
Recognize unique antigenic determinants: TCR and (MHC restricted-) Ig receptors
What are the components of the innate immune system?
Complement Pattern recognition receptors (PRRs) on immune cells Phagocytes Mast cell or basophils NK cells
What are the components of the adaptive immune system?
T lymphocytes, B lymphocytes, and complement
What are antimicrobial peptides (AMPs)? What are they produced by?
AMP are ubiquitous cationic proteins that play a role in innate immunity. They provide defense against bacteria and fungi viruses. Produced by keratinocytes.
What are the families of AMPs in humans?
Two families in humans:
o Human β defensins: HBD1, 2, 3
o Human cathelicidins: LL37 o Lactoferrins: hLF1-11
o Histatins
How do AMPs work?
Interact with phospholipids of microbial membranes, enter cell and mediate antiproliferative effects
Why are atopic dermatitis patients susceptible to staph aureas infections?
AMPs are decreased in a Th2 environment. Atopic dermatitis patients are susceptible to Staphylococcus aureus infection due to a decrease in AMP.
What environment are AMPs decreased in?
Th2 environment.
What is the function of neutrophils?
Phagocytosis and oxidative burst or free radical production
What is the function of monocytes or macrophages?
Phagocytosis and secretion of proinflammatory cytokines
What are two types of dendritic cells?
APCs (conventional) and antiviral (plasmacytoid)
What are the functions of eosinophils?
Antihelminthic, antibacterial, and secretion of proinflammatory mediators or free radicals
What are the functions of mast cells?
Antibacterial, antiviral, and secretion of proinflammatory cytokines
What are the functions of basophils?
Antibacterial, antiviral, and secretion of proinflammatory cytokines
What are the functions of NK cells?
Eliminates virus-infected cells and tumor cells (missing “self” hypothesis), and secretion of cytokines
What are the function of intraepithelial lymphocytes?
Secretion of proinflammatory cytokines (phagocyte activation and killing of infected cells)
What is the function of B-1 B lymphocytes?
Produce natural serum antibodies.