Chapter 16: Interferons and Complement system Flashcards
What cells are involved with Type 1 Interferons?
(1) Leukocytes [alpha interferons] (2) Fibroblasts [Beta interferons] (3) Produces antiviral proteins in neighboring cells
Mechanisms of Interferons: Alpha and Beta
(1) Virus infects (2) Signal sent to host cell nucleus (3) Viral replication activates host cell gene for interferon (4) Interferon is synthesized and released (5) Interferon binds to surface of neighboring cell (6) Cell stimulates antiviral protein and they float around waiting for virus to enter (7) Antiviral protein block viral replication by attaching to virus
Interferons action plan
(1) Interferes with virion replication in other cells (2) Specific to kill uninfected cells NOT already infected (3) Implement production of Antiviral Proteins (AVPs)
Mechanisms of interferon: Gamma
(1) Lymphocytes and NK cells do not have to be infected with virus for synthesis of gamma (2) Helps macrophages rid themselves of viruses (3) Enhances the activity of lymphocytes, NK cells and macrophages
Anti viral proteins works best against what?
RNA
Phagocyte cells (removes debris and pathogens)
Fixed macrophage, Neutrophil, Free macrophage, Eosinophil, Monocyte
Extracellular killing cells (destroys abnormal cells)
NK cells break down abnormal cells and ends in lysis
Multiple effects on inflammation
(1) Blood flow increases (2) Phagocytes activated (3) Capillary permeability increased (4) Complement activated (5) Clotting reaction walls off region (6) Temp increased in region (7) Specific defenses activated
Fever is the rise above what temp?
37 degrees celcius
Interferons are released by what type of cell
Lymphocytes (gamma and do not need to be infected), NK cells macrophages and infected cell
Classical Pathway includes which 3 complements initially and what goes on?
C1, C4, C2 (Antibodies bind to antigens such as microbes)
Alternative Pathway includes which 3 Factors and what goes on?
(1) Properdin pathway: Factor B, Factor D, Factor P (2) Activated earlier than classical (3) Activated by the contact between complement proteins and polysaccharides at the pathogen surface
Which complement factors are involved in inflammation?
C4a, C3a, C5a
Which complement factors are involved in opsonization?
C3b
Which complement factors are involved in membrane attack complexes
C5b, C6, C7, C8, C9