Immuno: Immune modulating therapies Pt.1 Flashcards
List some approaches to boosting the immune system.
- Vaccination
- Replacement of missing components (e.g. replacing immune cells)
- Cytokine therapy
- Blocking immune checkpoints
What happens when cells of the adaptive immune system engage with an antigen that it recognises?
Becomes activated - will proliferate and differentiate
What happens to T-cells when activated?
Proliferate and differentiate into effector cells (cytokine secreting, cytotoxic)
What are the two ways in which B cells can undergo clonal expansion once activated?
- They can differentiate into T-cell independent IgM plasma cells
- They can undergo a germinal centre reaction (T cell dependent) and become IgG/A/E memory and plasma cells
Which type of T cell undergoes a more pronounced proliferation following activation?
CD8 > CD4
List three types of antigen-presenting cell.
- Dendritic cells
- Macrophages
- B lymphocytes
What are some important characteristics of memory cells?
Longevity
- Memory T cells persist for a long time in the absence of antigen due to low level continual proliferation in response to cytokines
Different pattern of cell surface proteins involved in chemotaxis cell adhesion
- Allows memory cells to rapidly access non-lymphoid tissues
Rapid, robust response to subsequent antigen exposure
- Memory cells are more easily activated than naive cells
- B cell memory involves that circulation of pre-formed high-affinity IgG antibodies
What are the aims of vaccines?
- MEMORY – preformed antibodies, memory T cells, memory B cells, to provide long-lasting, protective immunity
- No adverse reactions
- Practical considerations – one shot, easy storage, inexpensive
Which cell surface receptor is used in the influenza vaccine?
Haemagglutinin (HA) - this is a receptor-binding and membrane fusion glycoprotein
ie. the reason influenza can infect cells
What are haemagglutination assays used for?
Describe how do they work.
Used to detect viral antibodies
How long does protection from the influenza vaccine last?
Starts 7 days after the vaccine and protection lasts for 6 months.
What agent is used in the BCG vaccine?
Attenuated strain of Mycobacterium bovis.
Describe the protection that is achieved by using the BCG.
- Some protection against primary infection
- Mainly protects against progression to active TB
NOTE : T cell response is important in protection against primary and progression to active TB
NOTE: protection lasts for 10-15 years
What is the Mantoux test?
- A small amount of liquid tuberculin (PPD) is injected intradermally
- The area of injection is examined 48-72 hours after the injection
- A reaction would appear as a wheel around the injection site (this is suggestive of latent TB, active TB or previous BCG)
What is a live attenuated vaccine? List some examples.
The organism is alive but modified to limit its pathogenesis.
V-BOY
Examples:
- MMR,
- Varicella zoster,
- BCG,
- Oral polio (Sabin)
- Yellow fever,
- nasal influenza, typhoid,
