T-cell and Humoral Effector Mechanisms Flashcards
(49 cards)
Individuals tending toward Th2 responses are more vulnerable to what type of infection?
Mycobacterial infection
Decreased expression of what causes T cells to migrate from high endothelial venules to lymph node?
CD62L (aka L-selectin)
What integrins do T-cells express and to what does each bind?
B1 integrin (VLA-4 which binds with VCAM-1) and B2 integrin (LFA-1 which binds with ICAM-1)
Antigen-specific activation of T cells upregulates what integrin and what does this do?
VLA integrins. Adheres T-cell to ECM to keep it from recirculating
What types of T-cells release IFNg?
CD8+ and (some) CD4+
What types of T-cells release TNF-a?
Some CD8s, some TH1s, and some TH2s
What cytokine is a potent macrophage activator and leads to NO production?
TNF-a
Whether IL-4 enhances or inhibits an immune response depends on the APC in use. In the case of which APC does it enhance immune response and which does it inhibit?
Enhances if B-cells are presenting, inhibits if Macrophages are presenting
GM-CSF
Granulocyte Colony Stimulating Factor. Stimulates WBC growth in bone marrow, is able to act over long distance for a cytokine
Three major cytotoxins stored in CD8+ cell granules
Perforin, Granzyme, and Granulysin (antimicrobial, apoptosis induction at high conc)
Name three cytokines who are limited to local action due to highly unstable mRNA
IL-2, IL-4 and IFN-g
What complement protein is Perforin analogous to?
C9
Another name for Fas
CD95
Is cell killing with Fas caspase-dependent or caspase-independent?
Caspase dependent (activates Caspase 8)
Lymphotoxin-alpha
A member of the TNF family, released by CD8+ T-cells to activate macrophages
Are mycobacteria typically processed by the MHC class I or MHC class II pathway?
Class II
What type of T-cell do macrophages use MHC class II to present their ingested peptides to?
Th1 (Type 1 CD4+)
What two things do Th1 cells do to pump up a macrophage which has ingested antigen to destroy it? (RAMPAGE!)
Release IFNg and stimulate the macrophage CD40 with CD40L
What do partially activated macrophages do to get T cells to completely activate them?
Secrete IL-12, which skews response toward Th1 (which activate the macrophage) and secrete IFNg (which further activates them)
What are the two forms of leprosy, which is bad, and what determines if someone has one course or the other?
Tuberculoid (not so bad) and Lepromatous (bad). People skewed toward Th2 responses (insufficient macrophage activation) have lepromatous
For each of the following give the mechanism it has devised to obfuscate the T cell response: mycobacteria, HSV, CMV, EBV, Poxviruses
Mycobacteria - inhibits phagosome fusion, HSV - ICP47 blocks TAP, CMV - targets MHC I for degradation, EBV - blocks proteasome and produces its own IL-10, Poxviruses - produces CR that block cytokine signals
Two molecules expressed in both effector and memory T cells, and two molecules expressed in both naive and memory T cells
Effector and Memory - CD44 (adhesion) and IFNg, Naive and Memory - CD45RA (modulates T cell signaling) and CD127 (part of IL-7 receptor)
Two types of Memory T cells and some distinguishing features of each
Effector Memory (do not express CCR7, express integrin and chemokine receptors, secrete IFNg, IL-4 and IL-5 after restim) and Central Memory (express CCR7, secrete less cytokines)
Give a brief moniker which describes each of the 5 immunoglobulin isotypes
IgD - membrane only, IgG - jack of all trades, IgM - produced first, activates classical complement, IgA - mucosal secretions, neutralize microbes and toxins, IgE - parasites, allergy
