Immune system
Describe innate immunity
always active, present at birth, responds rapidly, non specific, no memory
Describe a primary immune response.
-First exposure
-Slow
-Low magnitude
-Fewer effector cells
What is an epitope and antibody receptor?
Epitope: the specific part of an antigen that immune receptors bind to
Antibody receptor: B-cell receptor (BCR) located on the B-cell surface
Describe viral genomes
-Type of nucleic acid
-Single or double stranded
-Sense of RNA (pos or neg)
-Small
-Packaging
What do vaccines contain?
Weakened, killed, or fragment antigens
Describe adaptive immunity
developed over time and after exposure to pathogens, specific, slower response, has memory
Describe a secondary immune response
-Subsequent exposures to same antigen
-Very fast
-Much larger magnitude
-Due to the presence of B and T cells
-Basis for vaccines
What is humoral immunity?
Targets extracellular pathogens, preformed by B cells and antibodies
Describe the lysogenic cycle
-Host cell lives
-Viral DNA integrates into host genome
-Slower (usually dormant)
What does the body create in response to the vaccine?
-Memory B cells
-Memory T cells
What detects PAMPs (pathogen-associated molecular patterns)?
PRRs (pattern-recognition receptors)
What does a B cell receptor (BCR) do?
It recognizes free floating antigens
What is cell-mediated immunity?
Targets intracellular pathogens, preformed by T cells
Describe the lytic cycle
-Host cell dies
-Viral DNA replicates separately
-Fast
What does the vaccine do essentially?
Activates the primary immune response without causing disease
What happens when PPRs detect PAMPs?
What does a T-cell receptor (TCR) do?
What cell is selected for proliferation and what is proliferation?
-Only B or T cells who's receptor matches the antigen is selected
-Proliferation=rapid mitosis
What do viruses lack that causes them to not be able to reproduce?
-Enzymes=can't make ATP
-Cannot replicate DNA/RNA
-Cannot preform transcription or translation
After the vaccine, when real exposure occurs later what does the immune system do?
-Mounts a secondary response
-Is faster, bigger, and more effective
*Prevents illness or greatly reduces severity*
How does adaptive immunity develop?
-Antigen presentation
-Activation of T cells
-B cell activation
-Clonal selection and proliferation
What is a pathogen, antigen, and antibody?
Pathogen: Disease-causing organism
Antigen: A molecule from a pathogen that stimulates immune system response
Antibody: Secreted form of the BCR produced by plasma cells
What starts the immune response?
Macrophages
Describe retroviruses
-Have RNA genomes
-Carry out own enzyme reverse transcription
-Viral DNA integrates into host genome as provirus
-Host transcribes viral DNA