What are the characteristics of innate immunity?
- Present at birth
- Relies on pattern recognition
- Not specific
- No memory
- Primarily mediated by neutrophils
What are the characteristics of adaptive immunity?
- Slow (on first exposure)
- Adapts to antigen (not pre-formed)
- Highly specific
- Generates memory and improved immunity w/ repeated antigen exposure
What is specificity?
The ability to distinguish between different substances
Describe specificity with regards to innate immunity
Proteins that recognize common patterns of infectious organisms
Not very specific
Describe specificity with regards to adaptive immunity
Surface protein recognizes unique molecules
What is passive immunity?
Describe the characteristics of passive immunity
Transfer of pre-formed antibody from one person or animal to another
What are examples of passive immunity?
- Antitoxins for botulinum toxins
- Antibodies to rabies virus
- Maternal IgG antibodies crossing the placenta
- Maternal IgA antibodies in breast milk
What is active immunity?
Describe the characteristics of active immunity
Induction of an immune response (exposure to antigen)
What is an example of active immunity?
Patient AJ is planning to travel internationally in 3 days to a region endemic for Hepatitis A. She will be there for one year. What is the best type of immunity-based therapy to offer her to prevent infection?
Immunization against Hepatitis A with Ig and the inactivated virus
Which immunoglobulin do nursing infants have?
Which immunoglobulin do all very young infants (under 6 weeks) have?
(And Maternal IgA if they are nursing)
Which sort of immune response are infants under the age unable to generate?
Infants under 2 years old cannot generate an effective T-cell independent B cell response
(such as to a polysaccharide capsule)
Which sort of immune response do older adults have a decreased ability to generate?
T-cell independent B cell response
Which two groups cannot generate / generated reduced T-cell independent B cell responses?
- Infants under age of two
- Older adults
Struggle w/ encapsulated bacteria
Have greater frequency and severity of infections
Why are encapsulated bacteria particularly dangerous to infants under the age of two?
Infants under two cannot generate an effective T-cell independent B cell response
Why are encapsulated bacteria particularly dangerous to older adults?
Older adults have decreased ability to generate an effective T-cell independent B cell response
What must pneumoccal vaccines consisting of polysaccharides be conjugated to in order for children under the age of 2 to allow for a protective immune response?
What are cytokines?
Small proteins that are produced by cells and have effects on cells
Include chemokines, interleukins, lymphokines, tumor necrosis factors, interferons
What is the function of IL-2?
Promotes T cell growth and activation
What is "clusters of differentiation"?
Nomenclature system for the proteins used to identify cells
What does a CD refer to?
A protein expressed by cells
On which cells is CD3 expressed?
All T cells
On which cells is CD4 expressed?
What does CD4 bind to?
Helper T cells
Binds to MHC class II
On which cells is CD8 expressed?
What does CD8 bind to?
Cytotoxic T cells
Binds to MHC class I
On which cells is CD19 expressed?
All B cells
On which cells is CD56 expressed?
What is CD28?
What does it bind to?
Co-stimulatory protein on T cells (2nd signal)
Binds to B7 on APCs
A 33 year old woman is planning to travel internationally in 3 days to a region endemic for Hepatitis A. What is the best type of immunity-based therapy to offer her to prevent infection?
Due to short time before her potential exposure to Hepatitis A, she should receive immune globulin (Ig), which is passive immunization, since the antibody is preformed and the protection is rapid.
This protection is short-lived, so she should also receive inactive Hepatitis A vaccine, which provides longer protection.
Ideally, she would also have a booster in 6 months for much longer protection.
What protein must antigen-presenting cells express on their surface to present a peptide to CD4+ T helper cells?