UNIT1_GI_ImmuneSys Flashcards
(36 cards)
Talk to me about the Lone Star Tick. What can’t you eat after you are bitten by one of these buggers!?
NO RED MEAT!!!
Tick bites you –> foreign sugar gets inside you –> you mount an immune rxn to the sugar –> sugar is similar to molecule in red meat (mammals) –> you become allergy to red meat –> your life sucks from then on!
____________ cells: recognize antigen, attract macrophages
Th1 T helper
What do Th1 T helper cells secrete?
IFNy → activate M1 (inflammatory, “angry”) macrophages
IL-2 → helps CTL get activated when they recognize antigen
What kind of T-cells do you need to get rid of TB infection → without them get disseminated TB.
Need Th1 & M1-macrophages
_____________ cells: inflammatory role, more potent than Th1 cells
Th17 helper T-cells!
Th17 helper T-cells secrete what?
IL-17
○ Dendritic cells can make ___what IL___ → pushes differentiation into Th17.
IL-23;
IL-23 considered a central cytokine in Crohn Disease and UC.
______________ cells: stimulate macrophages to become M2 (alternatively activated) → wall off pathogens, promote healing.
Th2 helper T-cells
What is so special about M2 Macrophages?
wall off pathogens, promote healing
○ Typically occurs after pathogen killing Th1 response.
○ Important in parasite immunity if Th1’s M1 macs can’t kill invader.
○ Make IL-4 → attract eosinophils and macrophages
M2 Macrophages make IL-4 → attract ___________ & ___________
eosinophils and macrophages
_____________ cells: stimulated by antigen and migrate from T cell areas of lymph nodes into B cell follicles → help B cells get activated and make IgM, IgG, IgE, and IgA
Follicular helper T cells (Tfh)
What do Follicular helper T cells (Tfh) do?
help B cells get activated and make IgM, IgG, IgE, and IgA
Follicular helper T cells (Tfh) are stimulated by what cells/signals?
Tfh cells are stimulated by antigen and migrate from T cell areas of lymph nodes into B cell follicles
→ help B cells get activated and make IgM, IgG, IgE, and IgA
Make cytokines (IL-10, TGF-B) → suppress activation and function of Th1, Th17, and Th2 cells → keep immune response in check.
This are the actions of what immune cells?
Regulatory T cells (Treg)
What are the predominant T-cell type in a healthy gut?
Regulatory T cells (Treg)
_____________ cells: destroy any body cell they identify as foreign or abnormal antigen on surface presented on class I MHC.
Cytotoxic killer T cells (CTL):
○ Make IFNy → attract macrophages that eat cells induced to die via apoptosis.
What are the actions of CTLs?
destroy any body cell they identify as foreign or abnormal antigen on surface presented on class I MHC.
○ Make IFNy → attract macrophages that eat cells induced to die via apoptosis.
w.r.t T-cell development:
Pre T cells in the ____a____ proliferate → express T cell receptor via random V(D)J → use TCR to examine stromal cell surfaces with 3 possible outcomes:
(which are:???)
a. thymus
- Non-selection
- Negative-selection
- Positive-selection
w.r.t T-cell development:
Pre T cells in thymus proliferate → express T cell receptor via ____1____ → use ____2____ to examine stromal cell surfaces
- random V(D)J
2. T-Cell Receptor (TCR)
w.r.t T-cell development:
Which type of “selection” occurs when there is no affinity between the TCR and MHC?
Non-Selection: no affinity between TCR and MHC
w.r.t T-cell development:
Which type of “selection” occurs when there is a high affinity for self peptide in MHC → T cell dies by apoptosis (prevent autoimmunity) OR turns into a Treg.
Negative-Selection: high affinity for self peptide in MHC → T cell dies by apoptosis (prevent autoimmunity) OR turns into a Treg
w.r.t T-cell development:
Which type of “selection” occurs when there is a low affinity of the TCR to the MHC, T cell selected to mature.
Positive selection: low affinity, T cell selected to mature
Most cells begin as undecided precursors (Th0) located in ____1____ of lymph nodes → APC presents correct ____2____ in lymphoid tissues → divide and differentiate into Th1, Th17, Th2, Tfh, or Treg
- paracortex
2. antigen
Most cells begin as undecided precursors (Th0) located in paracortex of lymph nodes → APC presents correct antigen in lymphoid tissues → divide and differentiate into what types of immune cells? (5)
○ Th1
○ Th17
○ Th2
○ Tfh
○ Treg
