Exam 9: Chapter 11 Flashcards
What role do effector memory T cells hold?
They specialize in homing to inflamed tissues and functioning within them
Why are memory T cells harder to trace than memory B cells?
The TCR does not undergo somatic hypermutation or class switch recombination
When can the prevention of naïve B cell response be problematic?
When dealing with a pathogen that can mutate frequently
Why can the prevention of naïve B cell response be problematic?
It leads to the gradual weakening of the response to a pathogen and an increase in the severity of disease (original antigenic sin)
What are advantages of memory T cells?
Activated faster than naïve T cells, co-stimulation not required for memory T cell activation
What happens to the antibodies that are produces by plasma cells after infection?
They eventually degrade and disappear from the serum
How long do plasma cells make antibodies after infection?
A few months
What role do central memory T cells hold?
They make CD40L, and home to T cell areas of secondary lymphoid organs to interact with B cells
What do conjugate vaccines take advantage of?
The need for conjugate pairs between B and T cells
What allows memory T cells to survive for long periods of time?
IL-7 and IL-15 produced by activated naïve T cells make enough extra cytokine to maintain memory T cells
Why does the prevention of a naïve B cell response by circulating antibody make sense?
It allows for immune response resources to be conserved when responding to an invariant pathogen
What are vaccines designed to do?
Stimulate the production of memory cells
What cells do effector memory T cells differentiate into?
CD8+, TH1, TH17, or TH2 cells
How does a virus become attenuated?
A virus present in humans is grown in cells of other organisms and allowed to mutate; when transferred back to humans, the virus can no longer grow well in human cells and cause disease
What are the three purposes of a successful primary immune response?
Clear the infection, provide protection against immediate reinfection, provide long term immunological memory
What happens when a naïve B cell binds pathogen coated with specific antibody?
A negative signal is given to the naïve B cell to prevent its activation
Why are memory cells more effective in fighting infections?
- Memory cells are more sensitive and more easily activated
- Memory cells that recognize a particular antigen are more abundant than naïve cells that recognize the same antigen
- Memory B cells have undergone class switch, somatic hypermutation, and affinity maturation
- Activated memory B cells continue to undergo somatic hypermutation and affinity maturation
What happens when a memory B cell binds pathogen coated with specific antibody?
Memory B cell is activated and becomes an antibody-producing plasma cell
What would happen if an Rh- mother were not treated with anti-Rh IgG while carrying her first Rh+ fetus?
The secondary immune response would lead to massive destruction of fetal erythrocytes, causing life-threatening anemia in the second (and all subsequent) baby
What are the advantages that memory B cells have over naïve B cells?
High affinity BCR, lower activation threshold, quicker response, more efficient antigen processing, higher levels of MHC class II, differentiate faster
What consequence stems from the property that numbers of memory T cells are held constant?
When new memory T cells develop during the response to infection, older memory CD8+ cells must be lost to keep the population constant
What prevent s re-infection immediately after an infection is cleared?
Combined action of post-infection antibodies and the innate immune response
What are the two kinds of memory T cells?
Effector memory T cells and central memory T cells
