chapter 22 part 2 Flashcards
overview of the immune response
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PAGE 94!!!!!!!!!!!!!!!!!!!!!!
T cells
-4 types
- cytotoxic T cells
- Helper T cells
- Memory T cells
- suppressor T cells
cytotoxic T cells
- known as what 3 names
- what do they respond to
- killer T cells, CD8 cells, or Tc
- respond to antigens presented with MHC class I molecules
MHC
- stands for
- same or different for each person
- found where
- Major Histocompatibility Complex
- unique for each person
- on every cell in the body
Helper T cells
- known as what 2 names
- responds to what
- found only on
- function
- CD4 cells or Th
- responds to antigens presented with MHC class II molecules
- antigen presenting cells and other lymphocytes
- stimulates the response of both T and B cells
Memory T cells
-responds to what
responds to antigens they have already encountered
suppressor T cells
- known as
- function
- Ts
- inhibit T and B cells and moderate the immune system
T cell activation
-2 rules
- T cells cannot directly interact with antigen
2. T cells must have antigen presented to them on an MHC molecule
what do Th cells require
a specialized cell called an antigen presenting cell
antigen presenting cell
- definition
- 2 ex
- specialized cell that activates Th cell
- macrophages, dendritic cells
what occurs with Th cells
co stimulation occurs and T cell becomes activated
activated helper T cells secrete cytokines that will do what 4 things
- stimulate T cell divisions
- enhances non-specific defenses
- attracts and stimulates the activity of natural killer cells (NK cells)
- Promotes activation of B cells
what does stimulating the T cell divisions do?
-2 things
- produces memory T cells
- accelerate maturation of cytotoxic T cells
what does enhancing non-specific defenses do
attract and stimulate macrophages
what does promoting activation of B cells do
division, maturation and antibody production
cytotoxic T cells
- 5 steps
- antigen recognition
- costimulation activates CD8 T cell
- Activation and cell division (producing active Tc cells and memory Tc cells
- destruction of target cells
- perforin, cytokine, lymphotoxin release
perforin release triggers
- cytokine release
- lymphotoxin release
- destruction of plasma membrane
- stimulation of apoptosis
- disruption of cell metabolism
B cells are effective against
antigens and pathogens in body fluids; NOT infected cells
B cells
-4 steps
- binding of antigens to B cells
- sensitization of B cells
- activation by helper T cells
- B cell divides and differentiates into 2 cells
binding of antigens to B cells cannot what
cannot directly encounter an antigen and does not need an APC
sensitization of B cells
- what do B cells display
- what does it wait for
- antigens on MHC class II
- waits for signal from Th cell
activation by helper T cells
-2 steps
- Th binds to MHC class II complex on B cell
- Th secretes cytokines
cytokines
promotes B cell activation
B cell divides and differentiates into 2 cells
- plasma cell
2. memory cell
