Lecture 12 Flashcards
What is the linear theory for memory T cells?
Linear model: Come from effector cells that don’t die off after immune response is activated
What is the branched theory for memory T cells?
Branched model: effector and memory cells have separate fates
T-bet –> effector cells
Blimp-1 –> memory cells
What are the 3 memory T cell characteristics?
Last for years (most abundant in the body)
In peripheral tissue to respond to Ag
Have increased anti-apoptotic proteins (long survival)
What are the 3 type of memory T cells?
Resident (Trm)
Central (Tcm)
Effector )Tem)
Describe the characteristics of resident memory T cells. Where are they found and what do they produce?
Resident (Trm)
- In epithelium
- Produce IFN-y and TNF
Where are central memory T cells found, what do they express, and what does Ag recognition lead to?
Circulate in blood and home to LN and spleen
-Express CCR7 and L-selectin
Ag recognition leads to the proliferation of more EFFECTOR cells
Where are effector memory T cells found, do they proliferate, what do they produce, and what can they become if they enter the epithelium?
In blood
Do not proliferate
Produce IFN-y and TNF
Can become Trm cells if they enter the epithelium
When are memory T cells generated during a humans lifetime?
Infancy, youth, young adult
During adulthood are memory cells made? At what age does Senescence (stopping) of memory cells occur?
Few are made
65 years old
What causes the conversion of naive T cells to become memory cells
Thymic involution leads to the conversion of naive T cells to memory cells
What occurs at age 65 to cause the loss of proliferative capacity of memory cells from T cells?
Loss of CD28
What are the stimulating cytokines for Th1 cells?
IL-12 and IFN-y
What are the stimulating cytokines for Th2 cells?
IL-4
What are the transcription factors found in Th1 cells?
T-bet
STAT4 and 1
What are the transcription factors found in Th2 cells?
GATA3
STAT6
What are the cytokines produced for Th1 cells?
IFNgamma
What are the cytokines produced for Th2 cells?
IL-4. IL-5. IL-13
What are the effector functions of Th1 cells?
Activate resident macrophages
IgG production
What are the effector functions of Th2 cells?
Mast cell/eosin activation
IgE production
What 3 roles are Th1 cells apart of?
Chronic infections
Autoimmune disease
IC microbes
What 2 roles are Th2 cells apart of?
Helminth/parasite
Allergic disease
What are the stimulating cytokines for Th17 cells?
IL-1, IL-6, IL-23, TGF-beta
What are the transcription factors for Th17 cells?
RORyt
STAT3
What cytokines are produced by Th17 cells?
IL-17
What are the effector functions of Th17 cells?
NP, monocytic activation
-(maintenance of epithelial barrier)
Stimulate acute inflammation (IL-27)
What 2 roles do Th17 cells play a part in?
EC bacteria
Autoimmune disease
What are 2 important receptors found on T-reg cells and one transcription factor it produces?
** FOXP3+, CD3+, CD25+ **
What transcription factor do T-reg cells produce? And why is this important?
FOXP3+ cells that have a HIGH TCR self-reactivity
It is important because T-reg cells help us maintain tolerant to self-antigens
Describe the process of classical activation of macrophage resident cells.
Macrophage Resident Cell –> Production of Th1 cells and release of IFNy –> IFNy activates macrophages to have increased secretion of cytokines and increased phagocytic activity
What are the 3 properties that are increased due to the classical activation of macrophage resident cells?
Increased killing of microbes
Increased Th1 production
Increased T cell activation
Describe the process of alternative activation of macrophage resident cells.
Macrophage Resident Cell releases IL-4 –> Production of Th2 cells and release of IL-13, IL-4 –> Activates macrophage to release Il-10 and TGF-beta
What are the 3 properties that are increased due to the alternative activation of macrophage resident cells?
Anti-inflammatory events
Wound Repair
Fibrosis
What 2 cytokines do CD4+ T cells produce and what are their functions?
IL-2: Stimulates CTL differentiation
IFNy: Stimulates Macrophage resident cell to produce IL-12 which can help with CTL differentiation
Describe the characteristics of y∂ T cells. Where are they found, what do they recognize, what do they produce, describe their diversity in relation to alpha-beta T cells, and are CD4 or CD8 molecules present?
Found in epithelium
Can recognize NON-PEPTIDE ags (PAMPS or DAMPS)
Rapid production of cytokines
-d/t presence of “pre-activated” status
Smaller diversity that alpha-beta T cells
No CD4 or CD8 molecules
