Term
| what does NFAT stand for? |
|
Definition
| nuclear factor of activated T cells |
|
|
Term
|
Definition
| it works as a transcription factor involved in T cell expansion. |
|
|
Term
| is NFAT active when phosphorylated? |
|
Definition
| no. it is active when DE-phosphorylated. |
|
|
Term
| what does Calcineurin do? |
|
Definition
| removes phosphate from NFAT resulting in active NFAT and T cell expansion |
|
|
Term
| what does cyclosporine do to calcineurin? |
|
Definition
| inhibits it. thus prevents NFAT de-phosphorylation, thus preventing activation of genes involved in T cell expansion, resulting in a graft that is not rejected (cyclosporine is an immunosuppressive drug to prevent graft rejection). |
|
|
Term
| what could be a side effect of cyclosporine treatment? |
|
Definition
| infections because t cells arent being activated. |
|
|
Term
| T/F: CD4+ T cells are the main cytokine producers |
|
Definition
| true. thats why they're called T helper cells! |
|
|
Term
| what happens to the affinity of the IL-2 receptor when it goes from a naive T cell to an Activated T cell? |
|
Definition
| goes from LOW affinity to HIGH affinity (because it acquires a new alpha chain to make it stronger). |
|
|
Term
| what is the percentage of all lymphocytes for a specific bug after clonal expansion? |
|
Definition
| it was at 0.1% before and after is 10%-20% |
|
|
Term
| where do effector cells go ? |
|
Definition
| site of infection. DO NOT stay in lymphoid organs. |
|
|
Term
| How do effector cells know where to find the site of infection? |
|
Definition
| chemokine molecules that are secreted at the site of infection direct them to go there. |
|
|
Term
| what are the two forms of CD4+ T cell help? |
|
Definition
| 1) cell-mediated immunity help. 2) humoral immunity help |
|
|
Term
| Where is CD40L and what cell does it bind to? |
|
Definition
| its on CD4+ T cells. CD40 is on macrophages. Binding activates and allows killing. Can also activate B cells to produce antibody. |
|
|
Term
| What are the 4 different types of CD4+ T cells? how do they differ? |
|
Definition
| Th1, Th2, Th17, Treg cells. Differ in cytokine production. |
|
|
Term
|
Definition
| main function is to stimulate macrophage killing of bugs. . .also stimulates production of antibody isotypes involved in promoting ingestion of bugs (by phagocytes) and activation of complement (punches holes in pathogens to which an antibody molecule has already bound). |
|
|
Term
| what is the main cytokine produced by Th2 cells? and what does it do? |
|
Definition
| IL-4. stimulates production of IgE, causing mast cell degranulation (involved in allergies). Also produce IL-5 which activates eosinophils (which kill worms AKA helminthic parasites). |
|
|
Term
| the IL-10 secreted by Th2 cells does what? |
|
Definition
| inhibits activity of macrophages. suppresses Th1 cell-mediated immunity. Idea is balance of Th1/Th2 balance of cytokines. |
|
|
Term
|
Definition
| make IL-7 and IL-22. these cytokines promote inflammatory reactions. play a role in MS and IBS. |
|
|
Term
| how is the decision made to become a Th1, Th2, Th17? |
|
Definition
| NOT random. Determined by stimuli received like cytokines. Innate immune response may influence it. |
|
|
Term
| what is the balance of Th1/Th2 cells called? |
|
Definition
|
|
Term
| T/F: CD8+ T cells kill infected cells expressing antigen that their T cell receptor is programmed to recognize. |
|
Definition
|
|
Term
| Where does the T cell receptor programming occur? What are some of the steps involved in this programming? |
|
Definition
| Thymus. Generation of T cell receptor, positive and negative selection. |
|
|
Term
| what is the purpose of CD8+ T cell differentiation? |
|
Definition
| make proteins that do the killing. |
|
|
Term
| What are the two classes of memory cells and where are they found? |
|
Definition
| 1) central memory cell (in lymphoid tissue). 2) Effector memory cell (mucosal sites) |
|
|
Term
| difference between Central and Effector memory cells? |
|
Definition
| Central have rapid clonal expansion and wait for pathogen to arrive in lymph. Effector are ready for rapid reactivation when infections occur at peripheral site. |
|
|
Term
| what happens to lymphocytes after infection is cleared? |
|
Definition
| lymphocyte activation stimuli decreases and cells die by apoptosis. only memory cells remain. |
|
|
