Lectue 9 Flashcards
What do effector mechanisms depend on?
Type for pathogen, localisation and stage of infection
Which MHC molecule would be processed peptides from the microorganisms?
MHC class II (extracellular)
Where are MHC class I found?
On all nucleases cells (intracellular)
What type response is helpful in the cytoplasmic stage in intracellular?
TH1 response
What does the innate immune response in intracellular produce?
NK cells
What are some examples of innate defences?
Interferons and NK cells
What can viruses be?
Both intracellular and extracellular
What do viruses infect?
Host cells
What are the types of interferons?
Alpha and beta
What does increased levels of interferons do?
Slow the viral replication
How do interferons slow down that viral replication within a cell?
By increasing mx proteins, kinase pKR and upregulating the level of MHC class I on the surface
What happens when you stimulate NK cells?
Makes them angry and they are more likely to kill virally infected cells
What are chemokines?
They are a type of cytokine which tells cell to come to the area and increase the inflammatory response
What induces the synthesis of antiviral molecules?
IFNalpha and beta
What does IFN induce the synthesis of?
Degrades viral mRNA and inhibits protein synthesis
What are type I interferons?
Alpha and beta
What are type II interferons?
Gamma
What is gamma produced by?
NK cells and T cells
What does Type II interferons do?
Inhibits the TH2 response and promotes TH1 and recruits macrophages
What can recombinant interferon Alpha be used to treat?
Hepatitis B and C
What can be the side effects of using recombinant interferon alpha for hepatitis?
Flu like symptoms
What are NK cells a type of?
Innate lymphoid cells
What are NK cells?
Large granular lymphocytes
What do NK cells recognise?
Viral infectious cells
What can NK cells also recognise?
Stress cells in absence of MHC and immunoglobulins
How do NK cells kill?
By an extracellular mechanisms - performing and granzyme - which happens very fast
What are the two type of receptors for NK cells?
Activating receptors and inhibitory receptors
What do activator receptors recognise?
Carbohydrate ligands
What do inhibitory recepors recognise?
A motive on the side of MHC
What can viruses do?
Can reduce MHC expression
What do CD8+ cells recognise?
Viral peptides in the little groove of MHC class I
What type of activity do INFgamma have?
Antiviral
What are the two mechanisms that cytotoxic T cells use to kill?
Secretion of cytotoxic granules and FAS on the target cell
What are microtubules important for?
Targeting the granules on the surface so they can be controlled and released
Why is lysis developed?
In lysis
What antibodies can protect against flu?
Neuraminidasse and hemagglutinin
What is an example of versus specific immunity?
Using antibodies to neutralise free virus
What is an example for acquired immunity in viruses?
Antibody and cell mediated immunity
What is reduced when cytotoxic T cell responses increase?
Viral shedding
How do epidemics arise?
If the vaccine is wrong
What is an example of a specific immunity virus?
HIV
What does HIV target?
The immune system and attaches macrophages and dendritic cells
What does development of HIV lead to?
More infections
What is kapsoi’s sarcoma?
Herpes virus x
What disease do antibodies not protect?
HIV - if they did then there would be a vaccine
Patients with strong CTL have …..
Slower decrease progression
Virus mutations IN HIV lead to?
Progression of AIDS
What type of RNA virus is sars-cov2?
+ve RNA virus
What are some examples of parasites?
Round worms, tape worms and hook worms
What are some protective mechanisms from parasites?
Opsonisation, complement lysis and ADCC
How does ADCC work (antibody-dependent cell mediated cytotoxicity)?
Binds the antibody onto the surface and recognises the FC portion of the antibodies with FC receptors
What do helminths induce?
A strong IgE response
What are the role of helminths?
Mast cell mediated inflammation
What Protozoa can survive in macrophages?
Leishmania
What are the different effector mechanisms for malaria?
Sporozoite and merozoite may be susceptible to antibody, antibody may kill infected red blood cells and cytotoxic T clells active against infected liver cells
