Viro Lec - Part 1 Module 3 - Last part Flashcards
Activates the signaling cascade → resulting to induction of the interferon response genes in cells
Type 1 interferon (IFN)
cytokine central to both innate and adaptive immunity
Type II interferon or IFN-γ
Example of PAMPS
- Nucleic acids (viruses)
- Surface lipoprotein (viruses)
- Lipoprotein (bacteria)
- Capsule (bacteria)
Binding of PAMPs to PRRs stimulates?
transcription of numerous genes encoding proteins
class of PRRs
Toll-like receptors (TLRs)
TLRs bind ssRNA, detect RNA virus infections
TLR7 & TLR8
TLRs detects dsRNA
TLR3
Specialized lymphocytes; Lack an antigen-specific receptor (but can recognize PAMPS)
Natural Killer Cells (NK cells)
Increased MHC1 means?
will indicate a not stressed cell → The NK cell will detect → NK will initiate inhibitory signal → therefore no apoptosis
Decreased MHC 1 means?
→ will indicate an infected/ stressed cell → NK will detect it → it will make the cell undergo apoptosis → the cell will die → therefore there is no replication and it will eliminate the virus
NK cells have two types of receptors
○ Activating receptors (detect stress signals).
○ Inhibiting receptors (detect normal proteins like MHC molecules).
NK cells release granules containing:
Perforin & Granzymes (A & B):
Forms pores in the target cell membrane.
Perforin
Enter through the pores to trigger cell death.
Granzymes (A & B)
mediated by antibodies secreted by terminally differentiated lymphocytes called plasma cells
Humoral immunity
driven by cell receptors expressing lymphocytes
Cell-mediated immunity
when activated by infected cell, it will produce cytokines
T- Helper Cells
will directly and cause apoptosis of infected cell
Cytotoxic T Lymphocytes
Processes antigens from intracellular sources
Class I MHC Pathway (Cytosolic Pathway)
Processes antigens from extracellular sources
Class II MHC Pathway (Endocytic Pathway)
Cytosolic Pathway is recognized by?
CD8+ Cytotoxic T cells
Endocytic Pathway is recognized by?
CD4+ Helper T cells
Antibody found primarily in blood; first antibodies produced
IgM
Antibody principal class of Ab in blood and extracellular fluid
IgG
Antibody main antibody in secretions in respiratory, genital and GIT
IgA
Antibody very low conc. in blood and ECF; mediates allergic reactions
IgE
Antibody expressed almost exclusively as a cell surface molecule by naïve B cells
IgD
Types of Vaccines
● Live-attenuated virus vaccines
● Non-replicating virus vaccines
● Vaccines Produced Using Recombinant DNA and Related Technologies
Vaccines that elicits a lasting immune response while causing little or no disease; mimics a subclinical infection
Live-attenuated virus vaccines
Vaccines usually made from virulent viruses that are killed through chemical or physical agents but still maintain immunogenicity
Inactivated (Killed) Whole Virions
Vaccines that use lipid solvents (e.g. sodium deoxycholate) in enveloped viruses to solubilize the virion and release the components
Purified Native Viral Proteins
Deliberate insertion of several attenuating mutations into key viral genes or completely deleting nonessential genes that contribute to virulence
Attenuation of Viruses by Gene Deletion or Site-Directed Mutagenesis
Utilizes eukaryotic expression vectors such as plant and yeast cells, insect cells and various mammalian cells
Subunit vaccines produced by expression of viral proteins
Some nonenveloped icosahedral viruses have capsid proteins that self- assemble into virus-like particles (VLPs)
Viral Proteins that Self-Assemble into virus-like particles (VLPs)
Recombinant DNA techniques enable the insertion of foreign genes into viral genomes.
Viruses as vectors for Expression of Heterologous Viral Antigens
A type of vaccine that uses a bacterial plasmid to introduce DNA sequence (encoding an antigen) into an individual’s cells
DNA vaccines
measures only one limb of the adaptive immune response which is the humoral immunity
(Serological Diagnosis)
sample of choice for serological assays
serum
assays of choice for the qualitative or quantitative determination of viral antibodies; rapid, relatively cost-effective
Enzyme Immunoassay – Enzyme-linked Immunosorbent Assay (ELISA)
the gold standard for the detection and quantitation of virus-specific antibodies; the binding of antibody to infectious virus, thus preventing the virus from initiating
an infection in a susceptible cell
Serum (Virus) Neutralization Assay
simultaneously but independently measure antibodies against several proteins of the agent of interest
Immunoblotting (Western blotting)
widely used for viruses (e.g. influenza, parainfluenza) that hemagglutinate red blood cells of one or another species
Hemagglutination-Inhibition Assay
