Week 1 Flashcards
Which type of immune system can some animals leave with alone?
Innate / non-sepcific
Is the innate immune response passive or active?
Passive
Does the innate immune response have memory?
No
How quickly does the innate immune system act?
Immediately.
Outline the components of the Innate immune system.
A barrier of protection ( skin, mucosal surfaces etc)
Chemicals produced by these surfaces.
What important cells are part of the innate immune system?
Natural Killer Cells, Macrophages, Neutrophils, Mast cells.
What are the 2 divisions of specific immunity?
Humoral
Cell mediated
What is specific immunity driven by and reliant on?
Receptors
Does the specific immune response have memory?
Yes
What are the 3 main stages of the adaptive immune response?
Recognition
Activation
Response
What type of immunity do T and B cells use?
Adaptive
Are homopolymers or heteopolymers more immunogenic?
Heteropolymers
What are the main types of antigens?
Autologous
Allogenic
Heretologous
What are Autologous antigens?
Self antigens and there will be no immune response.
Do Autologous antigens cause an immune response?
No
What are Allogenic Antigens?
They are from the same species as the host and there may be reactions.
In what scenarios are allogenic antigens often present in the body?
Blood transfusions
Kidney transplants
What are Heterologous antigens?
They are from a different species to the hose so will be rejected and cause an immune response.
Do Heterologous antigens trigger an immune response?
Yes
What are homopolymers?
A polymer consisting of identical monomer units.
What are heteropolymers?
A polymer consisting of 2 of more different types of monomer unit.
What is the specific names of antibody binding sites?
Epitopes
What are Epitopes?
Anywhere on a particular molecule that has an antibody binding site.
What are Haptens?
Partial antigens
What kind of immune responses do Haptens cause and how do they do this?
They do not elicit an immune response alone but can bind to other carrier molecules such as proteins which then provoke an immune response.
Are Haptens antigenic ?
Yes
Are Haptens immunogenic?
No
Why aren’t haptens immunogenic ?
They cannot trigger an immune response without the presence of another carrier molecule such as a protein.
Where do B cells originate from?
The bone marrow
In which systems do B cells travel?
In the blood and lymphatic systems.
How is ‘tolerance’ created by B cells once they have settled in the spleen or lymph nodes?
B cells come into constant contact with both foreign and self-antigens. Binding with self-antigens triggers cell death. This is negative selection and gives rise to tolerance.
Where do B cells reside once they have traveled in the blood and lymphatic systems?
In the spleen and lymph nodes.
What allows B cells to be activated once they have resided in the spleen or lymph nodes?
The binding of foreign antigens to the B cells.
Where are T cells first from and what are they called initially?
Precursor T cells in the bone marrow
Which type of receptors do helper T cells use?
CD4 receptors
What MHC class do Helper T cells bind to?
MHC Class 2
Which class of MHC do CD4 receptors bind to ?
2
What type of receptors do cytotoxic T cells bind to?
CD8 receptors
What class of MHC do cytotoxic T cells bind to?
Class 1
What class of MHC do CD8 receptors bind to?
1
What type of receptors do T regulatory cells bind to?
CD4 and CD25
What type of organisms do B cells host defence against?
Bacteria
What type of illnesses do T cells host defence against?
Infections
When was the first vaccine created and by who?
Edward Jenner in the 1800s
Name some types of vaccines.
Whole Organism (attenuated or inactivated).
Purified Macromolecules.
DNA
Synthetic Peptide
Multivalent Subunit
What are the 2 different types of Whole-organism vaccine?
Attenuated
Inactivated
What are attenuated vaccines?
A live but weakened form of the disease.
What are the downsides of using whole cell vaccines?
They will be likely to produce an antibody reaction. However, it would be much more successful to trigger a Cytotoxic T cell response. The organism would have to enter the human cell for this to occur.
How are attenuated whole-organism vaccines produced?
Virulent pathogen is grown in adverse culture conditions or prolonged passage of a virulent human pathogen through different hosts.
How are inactivated whole-organism vaccines produced?
Virulent pathogen is inactivated by chemicals or irradiation with gamma rays.
What kind of booster do whole-organism attenuated vaccines usually require.
A single booster
What kind of boosters do whole-organism inactivated vaccines require?
Multiple boosters.
Are inactivated or attenuated whole-organism vaccines more stable?
Inactivated
What type of immunity is induced by attenuated vaccines?
Humoral and Cell mediated
What type of immunity is induced by inactivated vaccines?
Mainly humoral
Can attenuated vaccines revert to a virulent form?
Yes
Can inactivated vaccines return to a virulent form?
No
What are the positives of using Purified recombinant vaccines?
They can be done on a 1st scale and tend to be very safe.
What are the negatives of carrying out Purified recombinant vaccines?
They can be purely immunogenic so often require multiple doses.
They are expensive to produce.
What kind of immune response do Purified recombinant vaccines mainly trigger?
Mainly humoral
What factors can be used to improve vaccine efficacy?
Using adjuvants
How do DNA vaccines use work?
They don’t use antigens.
You use the gene sequences of a protein you want to vaccinate against in a vector. Once the DNA is inside the cells of the body, it will start to produce the antigen that you want to vaccinate against. This will hopefully trigger an immune response to the antigen.
How are DNA vaccines more specialised than other vaccine types?
Instead of just the antigen being produced, other molecules of a gene sequence could be included in the vector. This would allow you to decide what Cytokines are being produced and therefore you would be controlling the the of immune response.
What type of immune response is desired against a virus when using a vaccine?
A T-cell response
What are the advantages of using a DNA Vaccine?
Hypothetically, you could add more gene sequences to the vaccine to give it advantages.
What would be the advantage of adding Interleuken-1 gene to a DNA vaccine?
This will cause an amplified inflammation signal and therefore cause a greater T-cell response.
Blood vessels will also be caused to dilate, allowing more immune cells into the area.
What are the issues with DNA vaccines?
No DNA vaccines have been developed or used on humans yet.
Delivery of DNA vaccines has been an issue because they will need to form special delivery systems that can target different tissue types.
Outline how purified recombinant vaccines work
Use an antigen that is present on the surface of the pathogen and express this pathogen in other cell lines. This pathogen protein can then be purified into peptide which can then be injected into the host to trigger an immune response.
What are the issues with Purified recombinant vaccines?
When you express a protein in an alternative recombinant strain, sometimes the proteins don’t fold in the correct way and and a different structure is formed. This vaccine wold then not protect you from the real virus.
Sometimes only a small response is provoked. This means that booster injections are often needed to maintain a high level of protection.
Adjuvants are often needed to improve the potency of the vaccine.
What are the advantages of purified recombinant vaccines?
All proteins injected are likely to pass through the liver via the circulatory system and trigger an immune response.
When creating a vaccine, why may you not target the largest surface protein of a viral particle?
Although the largest surface proteins are usually the most potent, they may mutate more frequently and therefore they will not be complementary to the vaccine for very long.
When creating a vaccine, why would you be likely to target the largest surface protein of a viral particle?
Usually larger antigens have the greatest potency.
How is the mutation frequency of a virus found?
Using genome sequencing.
In what terms is the mutation frequency of a virus determined?
It is calculated as the number of amino acids or irons that change per chosen number of amino acids in the sequence.
Will a vaccine be more or less likely to mutate if herd immunity has occurred and why?
Less - a vaccine is more likely to mutate once it has spread and already infected a large proportion of the population.
What % of the population being vacated or becoming immune is herd immunity?
60%
What are subunit vaccines composed of?
Protein or glycoprotein components of a pathogen.
What are the advantages with subunit vaccines?
They can trigger a very strong immune response by only targeting the specific ‘germ causing’part of the pathogen.
They can be used on almost anyone including people with weekend immune systems and long term health issues.
In terms of a vaccine, why is a T cell response desired?
Cytotoxic T cells will kill infected host cells.
Helper T cells will regulate the adaptive immune response.
Memory T cells provide the immune system with memory against the specific antigen.
