Viruses For Research Flashcards
If viruses are given as vaccines do they produce an immune response
Yes
What are the 4 types of viral vaccine
Live / attenuated
Killed
Subtype
Gene delivery
What viruses are given in live vaccination and give example
Homologs which are less virulent eg vaccinia for small pox
Subtypes are giving either proteins from virus eg HA or NA from influenza or recombinant tech proteins, how
Protein can be removed from virus via detergent and purified
Or dna tech allows the gene for the protein to be cloned, amplified and then delivered from a vector eg yeast and purified
What kinds of genes can be delivered for vaccination
Spike protein gene which allows us to produce an immune response
How are the immune responses different in live/attenuated vs killed or subunit
Live produce both cell mediated response And also antibody production
Subtype or killed only produce antibodies
Why don’t killed or subunit ones produce a cell mediated response
They can’t reproduce
What is the most common way to attenuate a virus
Let it be cultured on 1 type of cell eg human
Then incubate it on cells of another host
This causes a drift/ mutation
It can no longer detect the previous host cells and can’t grow on them
How is a live recombinant vaccine (safe) made
The pathogenic gene from a virus is transferred to a viral vector and then injected rather than using a life virus itself
How is the covid vaccine an example of live recombinant vaccination
Adenovirus is used to insert the covid spike protein so that the sars virus doesn’t have to be injected
Still causes immune response
Why can viral dna be used for Virotherapy
They are easily manipulated eg to control its expression via promoters
They can easily infect and insert their dna eg via integrase enzymes
What is gene therapy
Converting a faulty gene into a new gene via viruses
What is ex vivo gene therapy
Cell removed from body and then manipulated with viral dna and then inserted back
Why is ex vivo gene therapy bad
Cells can be rejected
What is in vivo gene therapy
Replacing gene directly in body via virus / vector
What is an issue with in vivo gene therapy
Causes a immune response to the virus
What is an example of gene therapy to target cancer cells
CAR T chimeric antigen on T cells which identifies proteins on cancer cells
Is expression in gene therapy when using virus as a clone transient or permanent
Can be both depending on expression manipulation
Which virus is usually used in gene therapy and why
Adenovirus
Has a long time expression
What is oncolytic virotherapy
Where lytic viruses can target and kill cancer cells via using cancer cell proteins
Which 3 things happen after tumour lysis via virotherapy
Inflammation
Virus can affect other cells
Produces immune response due to tumour antigen release
What are the cons of oncolytic virotherapy
Some cancer cells are resistant to lysis
Virus causes an immune response
What is phage therapy
Using viruses to kill bacteria
What is major advantages of phage therapy
They kill specific bacteria only and also deal with bacterial resistance
What happens if phage therapy lyses gram -ve bacteria
Release of endotoxins (lipid A) which can cause sepsis/ inflammatory response
Why does phage therapy allow spread of bacterial resistance
Horizontal gene transfer
Which enzymes allow phages to leave bacteria and how
Lysins
They cleave the cell wall of bacteria
