Immunology - Immune Modulation Flashcards
What 4 immune modulators boost the immune response?
- Vaccination
- Replacement of missing components
- Cytokine therapy
- Blocking immune checkpoints (for advanced melanoma)
What 6 immune modulators suppress the immune response?
- Steroids
- Anti-proliferative agents
- Plasmapharesis
- Inhibitors of cell signalling
- Agents directed at cell surface antigens
- Agents directed at cytokines
What is the mechanism of vaccination?
- APCs present peptide to T cells (CD4 + CD8)
- Clonal expansion: T cells with appropriate specificity proliferate + differentiate
- CD4 cells: release cytokines + activate other cells (B cells)
- CD8 cells: kill infected cells
- Effector T cells then die by apoptosis OR surive as memory cells
- B cells differentate to T cells independent (IgM) memory cells, OR undergo germinal centre reaction (T-cell dependent plasma cells ((IgA/IgG/IgE))
- End result = immune memory (infection remembered + individuals remain protected)
How is immune memory achieved in vaccination?
- Residual specific T + B cells with enhance capacity to respond to re-infection
- Pre-formed pool of high affinity Abs
What are the 3 ideal vaccine requirements?
- Generates immunological memory
- Practical - single injection, easy storage, inexpensive
- No adverse effects
What is passive vaccination and how long does it last for?
- Directly administering pre-formed antibodies/immunoglobulins
- ~3 wks
What are some examples of passive vaccination?
- HNIG (Human Normal Ig) = Hep A + Measles
- HBIG (Hep B Immunoglobulin) + Hep B
- HRIG (Human Rabies Immunoglobulin) = Rabies
- VZIG (Varicella Zoster Immunoglobulin) = Varicella
- Paviluzimab (monoclonal Ab to RSV) = RSV
What is herd immunity?
When enough people in the community are immunised against a disease, it makes it more difficult for the disease to get passed between those who aren’t immunised
Why is vaccination less effective in the elderly?
- Immune senescence
- Nutrition (insufficient energy due to poor nutrition; reduced availability of trace elements + minerals (reduced gut absorption))
What is immune senescence?
The process of remodelling lymphoid organs - happens in the elderly
1. Increased frequency of terminally differentiated effector memory T cells
2. Increased expression of senescence markers
3. Much reduced production of recent thymic emigrants which drive the naiive T-cell repertoire
What is the evidence and concept behind dendritic cell/cancer vaccines?
Evidence:
- Acquired defects in DC maturation/function seen in some malignancies allows cancer to evade immune recognition
Concept:
- Pt WBCs harvested + cultured with target “tumour” antigen
- WBCs re-infused back into pt to stimulate immune response
What is an example of a dendritic cell/cancer vaccine?
Provenge (Sipuleucel-T) = Prostate cancer
What vaccinations are received at 2 months of age?
- 6-in-1
- Men B
- Rotavirus
What vaccinations are received at 3 months of age?
- 6-in-1
- Rotavirus
- PCV (pneumococcal conjugate)
What vaccinations are received at 4 months of age?
- 6-in-1
- Men B
What vaccinations are received at 1 year?
- Hib/Men C
- Men B
- PCV (pneumococcal conjugate)
- MMR
What vaccination can be given between 2-10yrs?
Flu (annually) = Sept/Oct
What vaccinations are received at 3yrs 4 months of age?
- DTaP/IPV (4-in-1 booster)
- MMR
What vaccination is given at 12-13yrs of age?
- HPV (6, 11, 16 + 18)
What vaccination is given at 14yrs of age?
- Men ACWY
- T/D/aP (3-in-1 booster)
What conditions make up the 6-in-1 injection?
- Diptheria
- Tetanus
- acellular Pertussis (Whooping Cough)
- Inactivated Polio
- Haemophilus influenza type B
- Hepatitis B
What conditions make up the 4-in-1 booster vaccine?
- Diptheria
- Tetanus
- acellular Pertussis
- Inactivated Polio
What conditions make up the 3-in-1 booster vaccine?
- Tetanus
- Diptheria
- acellular Pertussis
What adult vaccines are given and at what age groups?
- Flu (annually) = 50yrs +
- Pneumococcal (PPV) = 60yrs
- Shingles = 70yrs