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35 Cards in this Set
- Front
- Back
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what are the 3 types of effector T-cells
1. 2. 3. |
1. Cytotoxic T cells
2. TH1 cells 3. TH2 cells |
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what do CD4+ and CD8+ cells do after leaving the thymus and enter the blood stream:
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T cells recirculate between the secondary lymphoid tissues, the lymphatic system and the blood until it encounters its specific antigen
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... is the movement of naive T cells into secondary lymphoid tissues and is controlled by contacts made between ... on T cell and the endothelial cell
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homing
cell surface molecules |
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the secondary lymphoid tissues provide a means of allowing T cell ‘traffic’ to pass through a static site and:
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sample antigen presented by APC (in the form of peptide:MHC complex).
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what are the common APCs in secondary lymphoid tissues:
1. 2. 3. |
1. dendritic cells
2. macrophage 3. B cells (bind antigen, endocytose, degrade and present antigen) |
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what are the Adhesion molecules involved in T lymphocyte homing:
1. 2. 3. |
1. LFA- lymphocyte function associated antigen
2. CAM-cellular adhesion molecule 3. CCL21 |
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in the cortex of the lymph node, why are there interactions between the adhesion molecules on the cell surfaces that allow for non-specific binding so the antigen-specific interaction can occur
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even if a T cell encounter a specific peptide:MHC complex, the probability the molecules are close enough on both cell surfaces for binding to occur is very small
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in the cortex of a lymph node, As the T cell and APC adhere, their ... complex move into the plane provided by the adhesion site bringing them into close vicinity of one another. if the binding is specific, ... will form
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TCR and peptide:MHC
an immunological synapse |
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what are the 2 signals required for activation of naïve T cells:
1. 2. |
1. Binding of TCR to MHC class II
2. Binding of CD28 (on T cell) to B7 (on dendritic cell) |
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... sends an inactivation signal to the T cell to stop the proliferative response that was generated by the CD28
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CTLA4
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... cells are better a presenting antigen than ... and ...
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Dendritic
macrophage B cells |
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three main professional APCs:
1. 2. 3. |
1. dendritic cells
2. macrophage 3. B cells |
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where does professional antigen presenting take place:
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secondary lymphoid tissue
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All professional APC display the co-stimulatory molecule ... on their surface as a direct consequence of infection
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B7
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1. where are immature dendritic cells found
2. they express no ... and little ... |
1. under surface epithelial cells and in most solid organs
2. B7, MHC |
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... pick up antigen from periphery and migrate to secondary lymphoid tissue
Once they enter the T cell areas they lose their ability to take up antigen but begin to express high level of ..., ... and the ... |
Immature DCs
MHC class I and II B7 CAM DC-SIGN |
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... cells in the skin are an example of immature dendritic cells which become active APC called interdigitating reticular cells in the lymph node
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Langerhans
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macrophage have increased expression of ... and ... molecules once bacteria is phagocytosed
they recognize common bacterial antigens such as ... and ... |
B7
MHC LPS carbohydrates |
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in the B cell, Ig binds and ... antigen. in the absence of infection, B cells constitutively express high levels of ... and no ...
... not expressed until B cell becomes activated |
internalizes
MHC class II B7 B7 |
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IL-2 functions as ... signal the promotes ... proliferation after activation
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an autocrine
T cell |
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CD4 T cells help ... and ... to participate in the immune response,
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macrophages
B cells |
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after activation CD4 T cells differentiate along two pathways. what are the pathways and what do the cells do:
1. 2. |
1. TH1: secrete cytokines that lead to macrophage activation, inflammation, and enhanced phagocytosis
2. TH2: secrete cytokines that cause B cell differentiation and production of antibodies |
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CD8 T cells need stronger co-stimulatory signals than CD4 T cells to be activated
... are the only APC capable of delivering a strong enough co-stimulatory signal to activate CD8 T cells |
Dendritic cells
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naïve CD8 T cell and a naïve CD4 T cell simultaneously engage ...
the CD4 T cell becomes fully activated producing ... and ... The CD8, on the other hand, only produces ... and relies on the ... secreted by the CD4 T cells to ... its activation. |
an APC
IL-2 IL-2R IL-2R IL-2 induce |
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effector T cell is able to respond to specific antigen WITHOUT need for ...
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co-stimulation via B7-CD28 interaction
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in effector T cells there is a shift in adhesion molecule expression from ... to ...
this new adhesion molecule binds ... on endothelial cells of blood vessels in infected and inflamed tissues |
L-selectin
VLA-4 VCAM-1 |
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Effector T cells carry out their functions using molecules that falls into two broad categories. what are the categories and what do they do:
1. 2. |
1. Cytokines - alter behavior fo target cells
2. Cytotoxins - kill target cells |
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cytotoxic T cells are involved in the killing of:
1. 2. 3. 4. |
1. intracellular parasites
2. viruses 3. intracellular bacteria 4. protozoan parasites |
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CTLs contain stored ... that contains a mixture of cytotoxins that are used to kill ...
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lytic granules
infected host cell |
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CTL first bind their target cells through ... interactions
The formation of the immunological synapse causes a realignment of the ... and ... The CTL focuses release of ... at a small localized area of attachment |
nonspecific
cytoskeleton cytoplasmic components lytic granules |
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what is involved in the killing a viral infected cell:
1. 2. 3. 4. |
1. CTL recognizes infected cell via peptide:MHC complex
2. CTL programs target cell to die (apoptosis) 3. production of IFNγ to inhibit virus replication and to call on macorphages (they eliminate apoptotic cells 4. CTL moves to another target cell as first cell dies |
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Effector TH1 cells activate ...
Effector TH2 cells provide the co-stimulatory signal needed to trigger ... |
macrophage to eliminate vesicular pathogens
B cell proliferation and differentiation |
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TH1 cytokines will ... regulate TH2 cytokines and vice versa
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down
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what are the steps to macrophage activation (enhancing macrophage function):
1. 2. 3. |
1. TCR:coreceptor complex binding to peptide MHC II complex
2. Co-stimulation of macrophage via CD40L (TH1 cell) and CD40 (macrophage) 3. Activation of macrophage by IFNγ (produced by TH1 cell) |
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Circulating B cells make transient interactions with ... cells in the T cell zones
Upon recognition of ... and ..., adhesive interactions are strengthened and the B cell becomes trapped by the ... cell The binding leads to the synthesis of the ... (? cell) and ... (? cell) ... interaction drive the resting B cell to proliferate |
TH2
peptide:MHC complex TCR T CD40L T CD40 B CD40L:CD40 |
