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WVSOM Tlymphocytes
WVSOM T lymphocytes lecture 8 immuno
| Question | Answer |
|---|---|
| What are thymus derived lymphocytes? | T cell |
| What percentage of blood lymphocytes are made of T cells? | 60-90% |
| Where do T-cell progenitors develop? | birth in bone marrow and migrate to the Thymus gland to get their education and develop |
| Where are the T cells? | the majority of the lymphocytes in a patients blood about 60 to 90 % |
| What are the major functions of T cells? | some are killer cells they will kill an infected cell or tumor cell, but a lot act as regulator to control the immune response by helping b cells by helping macrophages and other T cells |
| Do T cells have any inhibitory function? | yes they can suppress an immune response it will be a major player in bringing the immune response back to normal after it has kicked in |
| Only T cells that do not respond to self are the ones released from where? | thymus |
| What are some regulator functions of T cells? | helper functions, cytotoxic function |
| What are the helper function of the T cells involve B cells? | include helping B cells form antibody |
| We can divide most of the T cells into two groups of expression what are they? | CD4, and CD8 |
| What are the function of T cells with CD4 or CD8 expression? | CD4 are helpers or regulators, CD8 are cytotoxic its going to kill another cell |
| All functional cells will have what type of CD proteins? | CD3 |
| What are the major subset of CD8 expressed T cells? | killer cells |
| The major subsets of CD4 are what? | TH1, TH2, TH17, and so called regulatory cells |
| How do you define the subsets of CD4 T cells? | they are defined by the cytokines they produce |
| TH1 which are CD4 positive T cells express what cytokine? | interferon gamma |
| What do type 1 interferons do? | have an inhibitory effect on viral |
| What is the main function of interferon gamma? | primarily activate macrophages to increase their phagocyte ability so they can kill things intracellularly better than a normal macrophage |
| TH2 helper T cells are defined by what cytokines? | Interleukin 4, IL 5, IL 6, IL 10, IL 13 |
| What do all of the interleukins that TH2 express have in common? | they help B cells become activated and release antibody so they help to regulate antibody responses by helping B cells |
| What immunoglobulin does IL4 help to produce? | IgE |
| Do TH1 interact with TH2? | yes they interact and regulate one another |
| TH17 are a new set of T cells that produce what cytokine? | IL 17 |
| What is the function of TH17? | they participate in the inflammatory response they help to recruit neutrophils |
| What is the function of T regulatory cells? | they inhibit, they suppress the immune response |
| One of the regulatory T cells that is seen often expresses CD4 and may also express what? | inhibitory cytokines being; transforming growth factor beta (TGF beta) and IL10 |
| What cytokines tend to have inhibitory activities? | Transforming growth factor beta (TGFbeta) and IL 10 produced by regulatory T cells |
| What are the main two recognition types on T cell receptors and what do they form? | alpha and beta, they form domains and those domains can form a variable region on top and constant on bottom |
| Just like the antibody on the B cell receptor, the T cell receptor has very little cytoplasmic component so how does it send a signal down to the nucleus? | other proteins associated with it that has significant cytoplasmic components and some of these we call CD3 |
| What is CD3 and what is it involved in? | a group of proteins on the surface of all T cells and they are involved in activating T cells |
| Why do we have so much variability in T cell receptors? | Each of those proteins of a T cell receptor is encoded by different gene segments of which we have several to chose from and different combinations of that gene segment creates all that variability. |
| What are the regions that the alpha receptor on a T cell can choose from? | V, J, C |
| What about the beta region on the T cell what are the regions it can choose from? | V,D,J,C |
| What is involved in the signal that activates the T cell after it comes in contact with the antigen? | The signal involves kinase enzymes involving a phosphorilation reaction in a cascading event that also involves intracellular calcium |
| What is the end result of all the phosporilation reactions in the presence of calcium in a T cell? | the activation of transcription factors which tells the cell to transcribe or translate cytokines or to go into the growth cycle or do something else |
| Why is CD 3 so important to the T cell? | they are there with the receptor, when the receptor binds to an antigen the CD3 becomes phosphorilated and the cascade starts |
| Where do the T cells come from? | they develop and mature in the thymus gland |
| What happens if it recognizes self? | they die by apoptosis in the thymus gland |
| So what happens to T cells in the thymus? | Mature form a functional T cell receptor, those that bind to strongly to self are eliminated as part of the education process, and they form a receptor that will bind to peptides in the proper context |
| What happens to the T cells once they have matured? | they go to secondary lymphoid tissue if they encounter antigen they will be activated and does its effector function or become memory cells |
| What is the principal effect of IL 2? | T cell growth, T and B proliferation |
| What is the principal effect of IL 3? | growth of early hematopoietic progenitor cells |
| What is the principal effect of IL 4? | B cell proliferation ; IgE production |
| What is the principal effect of IL 10? | inhibits macrophage and dendritic cells |
| What is the principal effect of IL 13? | IL 4 like effects |
| What is the principal effect of IL 17? | induces inflammatory cytokines and PMN |
| What is the principal effect of INF gamma? | macrophage activation |
| What is the principal effect of TGF beta? | inhibitory; anti-inflammatory |
| How can you tell if the patient has a certain quantity of T cells in the blood? | flow cytometer with antibodies |
| How do you differentiate CD4 from CD8? | antibodies |
| What would be the effect of depleting CD4 T cells on an individual’s ability to resist infection? | extremely devastating because all the helper and antigen presenting cells are CD4 positive |