Block C Lecture 3: Activating T Cells and B Cells Flashcards
What type of interaction is the physical interaction between T cells and APCs?
A cognate interaction (direct cell-cell interaction)
(Lecture 3, Slide 4)
Why is the cognate interaction between CD (T cells) molecules and MHC molecules in the T-cell APC cognate interaction critical to mounting an effective immune response?
As it helps activates T cells
(Lecture 3, Slide 6)
What type of cells do cytotoxic (CD8+) T cells kill?
Virally infected cells
(Lecture 3, Slide 6)
What 3 things are involved in the cognate interaction in CD8+ T cell effector function?
It involves MHC class 1, TCR (with CD8), and a costimulatory signal (B7-CD28)
(Lecture 3, Slide 8)
What signals does the Antigen-Presenting Cell (APC) send to CD8+ T cells after antigen recognition?
Signals for proliferation
(Lecture 3, Slide 8)
What 2 ways do APCs send proliferation signals after cytotoxic (CD8+) T cells have recognised the antigen?
Upregulation of the IL-2 receptor
Production of its own IL-2
(Lecture 3, Slide 8)
What does upregulation of IL-2 receptor mean?
The cell expresses more of the receptor in response to a specific signal, in this case a proliferation signal sent by an APC
(Lecture 3, Slide 8)
How does IL-2 cytokine act as a signal for proliferation to cytotoxic (CD8+) T cells?
By binding to its receptors on the T cell
(Lecture 3, Slide 8)
What does the IFNγ (interferon gamma) signal instruct cytotoxic (CD8+) T cells to do?
Differentiate and kill
(Lecture 3, Slide 8)
What 4 things are involved in a Th2 cell interacting with a B cell?
Th2 T cell, B cell, BCR, MHC Class II receptor (with co-stimulation from CD40-CD40-L)
(Lecture 3, Slide 9)
What is the purpose of a Th2 cell interacting with a B cell?
In order to help the B cell proliferate
(Lecture 3, Slide 9)
What 3 cytokines do Th2 cells secrete after interacting with B cells, in order to get B cells to proliferate?
IL-4, IL-5 and IL-6
(Lecture 3, Slide 9)
What 2 things can B cells differentiate into after being signalled to proliferate by a Th2 cell?
Resting memory cells or antibody secreting plasma cells
(Lecture 3, Slide 9)
What are the functions of Th1 and Th2 helper T cells?
Th1 secretes IFNγ (interferon gamma) and activates macrophage function
Th2 secretes IL-4 and helps antibody production by activating B cells
(Lecture 3, Slide 10)
What are 3 types of helper (CD4+) cells, other than Th1 and Th2 cells?
Th17
TFH
Treg
(Lecture 3, Slide 11)
What is the function of Th17 helper (CD4+) T cells?
The are important in the response to extracellular bacteria and lead to production of neutrophils
(Lecture 3, Slide 11)
What is the function of TFH helper (CD4+) T cells and where are they found?
They are found in the follicles (germinal centres) and are important to help B cells produce antibodies
(Lecture 3, Slide 11)
What is the function of Treg helper (CD4+) T cells?
They downregulate immune responses and help prevent harmful immune responses or autoimmunity
(Lecture 3, Slide 11)
What is differentiation of T cells regulated by?
Cytokines
(Lecture 3, Slide 12)
What 2 things does recognition of an antigen by a BCR result in?
Activation of the B cell and internalisation of the antigen
(Lecture 3, Slide 17)
What happens when a B cell activates?
It secretes antibody of the same specificity of its BCR
(Lecture 3, Slide 16)
What happens after a B cell expresses its functional BCR?
It matures from the primary bone marrow and migrates to the periphery via the lymph nodes
(Lecture 3, Slide 16)