Viro Last Chapter Flashcards
What proteins mark invading pathogens or infected cells for destruction? Activation leads to efficiently clear virus infected cells y destruct of viral particle.
Complement
The inflammatory response is mediated by ______ and migrating leukocytes.
Cytokines
Macrophages localized in tissues are activated by infection and kill viruses o infected cells using what?
Toxic O2 compounds
Virus infected cells secrete what?, which protects nearby cells against virus infection.
Interferons
Interferon signal transduction is carried out by what pathway?
Jak-Stat pathway
Antiviral activities are induced by _____.
Interferons
What are the 3 interferons induced systems that are understood in some detail?
- My proteins
- 2’ 5’ -oligo(A) synthesis y ribonuclease L ((the oligmers bind to y activates rL, which degrades viral y cellular mRNAs))
- PKR (double stranded RNA dependent kinase) ((blocks initiation of protein synthesis))
Since plants, invertebrates, y fungi don’t produce interferons, they use what instead?
RNA interference (RNAi)
What is an important antiviral defense mechanism?
RNAi (interference)
Which immunoglobulin is the the most abundant?
IgG
What are used to control gene expression in vertebrates?
MicroRNA (miRNA)
Once in the cytoplasm, miRNA precursors are further processed into miRNAs by _________, the enzyme ivolved in the generation of siRNAS.
Dicer
miRNAs are typically made from what?
Imperfect RNA hairpins
This type of immunity is based on humoral y cell-mediated responses.
* uses B y T cell lymphocytes * slower to develop (5-6days) * highly specific to individual Ag molecules * use randomly generated Ag receptors
Adaptive Immunity
Viruses y other infectious agents produce a variety of proteins y other macromolecules that are recognized by the host as foreign; these molecules give rise to specific immune responses called what?
Antigens
This vaccine is based on live organisms that are either nonpathogenic in humans or known as “trustworthy”. They can be genetically manipulated to express one or more viral proteins.
(New categories of antiviral vaccines)
Chimeric Vaccines
What are the primary organs of the immune system?
Bone Marrow and Thymus
What virus does this vector belong to?
Advantage: doesn’t require cell division for transgene expression.
Limitations: doesn’t integrate their genome into cellular chromosomes.
Adenovirus vector
What are the secondary organs of the immune system?
Spleen, Lymph nodes, y gut
Which influenza envelope protein reverses the binding (sialic acid) by cleaving the bound sialic acid residue, releasing progeny virions from cell surface.
(Basically, it assist in viral budding and release)
Neuraminidase (NA)
True or False:
MHC I found only on Ag-presenting cells.
False.
MHC II is found only on Ag presenting cells
MHC I is found on nearly every nucleated cell
What virus does this vector belong to?
Advantage: integrate their genome efficiently into cell chromosomes
Limitations: can generate replication
Retrovirus vectors
Which influenza envelope protein reverses the binding (sialic acid) by cleaving the bound sialic acid residue, releasing progeny virions from cell surface.
(Basically, it assist in viral budding and release)
Neuraminidase (NA)
True or False:
MHC I found only on Ag-presenting cells.
False.
MHC II is found only on Ag presenting cells
MHC I is found on nearly every nucleated cell
What are the effects of interferons on the immune response? (3)
They stimulate Ag processing y presentation.
Increases MHC proteins y enhance T cell activities.
Enhances the immunogenicity of viral proteins.
Specific parts of the Ag that is recognized by antibodies (B y T)
Epitopes
T lymphocytes respond to peptides on the surface of what kind of cells?
Antigen Presenting Cells
Which immunoglobulin causes an allergy response?
IgE
What recognizes virus-infected cells y kill them by apoptosis pathways, such as secreting cytotoxic proteins like Perforin?
Natural Killer Cells
What is the name of the successful protease inhibitor of HIV-1 that was developed by rational methods?
Ritonavir
Louis Pasteur looked at infected rabbit what? To prepare a rabies vaccine.
Spinal cord
True or False?
Active immunization is self generated and stimulate immune memory. (Induces an immune response by exposure to a vaccine)
True!
It Active also has natural=recovery from infection and artificial=from vaccination
*Passive Immunization is obtained from other source.
Natural=passed from mama
Artificial=administration of anti-venom
What are the 4 types of antiviral vaccines? Describe.
- Live Wild Type viruses: virus that can infect one spp and used to infect another spp to protect against a closely related patho.
- Live Attenuated V: reduces the virulence of a pathogen while viable.
- Inactivated V: pathogenic virus that has been grown in a culture and killed with formaldehyde.
- Subunit V: consist of purified viral proteins that are immunogenic.
They include nano particles bearing viral antigens.
New categories of antiviral vaccines
VLPs
This vaccine has hundreds y even thousands of peptide Epitopes.
(New categories of antiviral vaccines)
Multitalented Peptide vaccines
True or False?
Inactivated virions or purified proteins (subunit v) often do not induce the same immune response as live attenuated vaccines.
True!
Unless mixed with an adjuvant (a substance that is added to a vaccine to increase the body’s immune response).
What were used as adjuvants in human vaccines?
hint: element
Aluminum salts
What are the other delivery systems for viral Ag besides Target, Vector, New material? Give examples of some other than injection. (4)
Aerosol.
Nasal.
Food (bananas).
Gene gun.
This term* starts with the identification of a viral gene protein that would make a good drug target.
Target Based High Throughput Screen
What virus does this vector belong to?
Advantage: doesn’t cause disease (safe to humans)
Limitation: small insert size
Adeno-Associated Virus
What blocks ion channels y inhibits uncoating of influenza virions.
Amantadine
This vaccine is based on DNA plasmids that code one or more viral proteins that can be expressed in host cell.
(New categories of antiviral vaccines)
DNA Vaccines
What are the 4 major objectives that virus vectors have been designed for?
- Vaccination against diseases.
- Anti cancer agents that kills tumor cells.
- Gene therapy to replace deficient genes.
- Production of specific proteins.
What happens if NA (neuraminidase) activity is blocked?
NA can cut the host cell receptor y the virus can’t be released from host’s cell.
How do vaccines work?
They work pq the immune system can recall the identity of a specific virus years after the initial encounter
~immune memory
