7 T Cell Effector Mechanisms Flashcards
What is different about an armed effector T cell?
No costimulation needed for action
New adhesion molecules expressed
What are the new adhesion molecules of effector T cells?
CD44: binds ECMatrix hyluronic acid
LFA 1
CD2
What important adhesive molecule do effector T cells not express?
L Selectin which allows entry to secondary lymph
What are the three main types of effector T cells?
CD8
CD4: Th1 and Th2
What are CD8 T cells?
Cytotoxic (killer) -kill viral infected cells
What are CD4 T cells?
Helper -orchestrate B cell response
What is the main difference between Th1 and Th2 T cells?
Th1 activates macrophages in addition to B cells
What is the main ligand made by both CD4 Helper T cells?
CD40
What other cytokines do Th1 cells make?
IFNy GM-CSF TNF-a LT IL3
What general class of infection activates Th1 and Th2 productions?
Th1 - Intracellular
Th2 - Extracellular
What types of class switching will Th1 Helper T cells induce in B cells?
Intracellular antibody classes
What types of class switching will Th2 Helper T cells induce in B cells?
Extracellular antibody classes
What two varables determine Th0 differentiation?
Cytokine Millieu
Antibody Concentration
What cytokines induce Th1?
IFNy
IL12
What cytokines induce Th2?
IL4 and IL6
What are the transcription factors for Th1, Th2, and Treg cells?
Th1: T-bet
Th2: GATA 3
Treg: Foxp3
What antibody concentration induces Th1?
High
What antibody concentration induces Th2?
Low
What is an overview of CD8 effector mechanisms?
Perforin, Granzymes/Granulysin
IFNy production to recruit
Fas ligand to induce apoptosis
What does CD8 recognition (not effect) require?
TCR binding to MHC class I CD28 binding to B7
What does any T cell proliferation require?
IL2 and IL2 receptor production in tandem
What are the main adhesion molecules of CD8’s?
LFA 1 to ICAM 1
What is an overview of CD4 effector mechanisms?
CD40 on APC recognized
IFNy produced
Macrophage/B cells infiltrate
Who is the maestro of the immune response?
Helper T Cells
What signal induces macrophage production in the bone marrow?
IL3 plus GH-CSF
What signal causes macrophages to accumulate at the site of infection?
CXCL2
What pathway do cytokines signal through?
Jak-stat dimer signal cascades
What are the cytokines he wanted to know?
- IL2: Induces T cell growth
- IFNy: Activation of MHC class I and Class II in macrophages
- LT: Macrophage activation, induces NO production
- IL4: B cell activation, growth, IgG1, IgE, up MHC, class E induction
- T cell growth and survival
- IL3: Hematopoetic cell growth factor for progenitor hematopoetic cells (needs CSF)
- TNFa: Macrophage activation, induces NO production
- GN-CSF: Hematopoetic cell increase in granulocytes and macrophage differentiation and dendritic cells
