Cell-Mediated Cytotoxicity - Diebel Flashcards
How is humoral immunity mediated and what does humoral immunity protect?
Mediated by Antibody
Protects extracellular environment
How is cell mediated immunity effective?
Recognizes pathogen infected cells or cells that have undergone genetic alterations and kills them
What does cell-mediated cytotoxicity provide defenses against?
Viruses
Bacteria
Parasites
What are antigen non-specific effector cells?
NK Cells (Macrophages, Neutrophils, Eosinophils)
What are antigen specific effector cells?
CD8+ T-Cells
CD4+ T-Cells
What does an NK cell respond to in order to mediate cytotoxicity?
Lack of MHC Class I Molecule
Stress Induced Activating Ligand
What does a CD8+ T-Cell respond to in order to mediate cytotoxicity?
Antigen recognition as Non-Self
CTL-Precursors lack the ability to do what?
Proliferate and Kill
How is a CTL-P activated?
Licensed APCs
How are APCs licensed?
Th1 or Th17 CD4+ T-Cells
PAMPs on TLRs
What signals from the APC is required to activate a CTL-P?
Antigen presented on MHC Class I
CD28 :: CD80/86
IL-2 from Th1 or Th17
IL-4, IL-13, IL-15
Describe the alpha receptor on a naive CD8+ T-Cell
Low affinity IL-2 Receptor
Describe the CD25 receptor
High affinity Gamma, Beta and Alpha IL-2 Receptor
What do naive CTL-P cells express?
Low levels of CD44 and LFA-1
High levels of L-Selectin and CCR7 (retention in lymph node)
NO IL-2
What do effector CTL cells express?
High Affinity IL-2R (CD25) and IL-2
Low levels of L-Selectin and CCR7
High levels of CD44 and LFA-1