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66 Cards in this Set
- Front
- Back
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Which cytokines are pro-inflammatory? |
TNF (tumor necrosis factor) IL - 1 IL - 6 |
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What induces the production of IL-1 and IL-6? |
TNF |
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What is the anti inflammatory form of IL-1? |
IL- 1ra (no strong signal, no effect) |
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Principle funciton of Th1? |
regulation/ mediation of cell mediated immunity and regulate against INTRAcellular pathogens inside the host cell. |
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TH2? |
regulation/ mediation of humoral mediated immunity and regualte against extracellular pathogens outside the host cell. |
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Bacterial superantigens (SE) bridge what? |
bridge TCR and MHC II in absnce of specific peptide |
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In innate immunity what are the 1st line and 2nd line responses? |
1st line: skin, mucous membranes, normal gut flora 2nd line: immune cells, inflammation, Complement, Antimicrobial substances. |
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Differentiate between innate immunity and aquired immunity |
Innate: fast response, fixed, limited specificity, constant during response. Aquired: slow response, variable, a number of highly selective specificity, imrpoves during response. |
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Differentiate between Pattern recognition receptors (PRR) and Toll like receptors. |
PRR: recognize pathogen associated patterns on cell surfaces. Toll like receptors: like PRR except they are immobilized and cell mediated. |
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What are the receptors in innate immunity? |
PRR Toll like NK Complement Fc receptor |
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Strength of a response depends on what? |
How strong the ligand and receptor bind. |
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When is a perfect antigen deemed an immunogen? |
When the perfect antigen can elicit a strong recognition and binding which results in strong response. |
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What criteria do immunogens need to meet? |
1. Foreign 2. High molecular weight 3. Chemically complex 4. Degradation |
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What is a hapten? |
A unconjugated (unpaired) substance that is unable to initiate an immune response when uncoupled. |
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What is an epitope? |
An antigenic determinent. It is the smallest part of an anitgen that binds to antibodies or specific receptor. |
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Which antigens are excellent immunogens and are poor immunogen? |
Protein = EXCELLENT Immunogen Nucleic Acid = POOR immunogen. |
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Activated B cells will produce 2 types of cells which are what? (clonal selection theory) |
plasma cells and/ or memory cells |
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what is the most distinguishing factor of innate immunity? |
NON specific and NO memory!!! |
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NK cells come from _______ cells but function for the _______ |
come from aquired but function for innate. |
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What are examples of granulocytes? |
Neutrophils, Eosinophils and basophils. (BEN) |
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___________ are considered APC cells |
Macrophages |
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Describe killing of bacteria via neutrophil. |
Neutrophil phagoctyosis the bacterium and fuses with granules. The pH will increase(basic) and lead to activation and bacterium is killed. When pH decreases (Acidic) this will allow lysosomes to attach and lead to breka down of bacteria --> apoptosis. the remaining neutrophil apoptosis is phagocytosed by a macrophage. |
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Natural Killer (NK) cells |
- Healthy cells have an inhibiting receptor to prevent NK cells from attacking healthy cells. Once healthy cell is infected, it releases a receptor for NK to come and kill virus. - Kill through Perforin Pores (perforin forms pores in cytoplasm of target cells so NK can get through and either cause cell lysis or apoptosis. - NK KILLS CELLS THAT LACK MHC I |
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What acts as a bridge between innate and aquired immunity? |
Complement system. |
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C3 is broken down by C3bBb convertase. Explain the next step. |
C3 --> C3b and C3a C3b (opsinization) - bines and causes opsinization of bacteria to make them more recognized by macrophages. C3 a (C5a) - recruits phagoctyres and stimulates neutrophils by anaphylatoxins |
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What is the function of C5b? |
C5b - forms MAC (C6-C9) which is inbedded in membranes and causes cell lysis.
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What is the role of Cytokines? |
mediators between cells/ cell communication. humoral factor, soluble - product of Activated macrophage. |
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What is the function of Interferon Type I (cytokine of innate immunity) |
Type I: Produced by every cell in the body and is apart of innate. Inhibits viral replication, activates NK cells, increases MHC class I. Interferons are released by the infected cell. |
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Which cells are responsible for INTRAcellular killing? |
Macrophage and Neutrophils |
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Which cells are responsible for EXTRAcellular killing? |
NK and Eosinophils. |
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Which immunoglobin (Ig) is known as the workhorse of the immune system? |
IgG |
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What is Anti body- dependant cell mediated cytotoxicity (ADCC)? |
Killing of antibody via cytotoxins and granules to activate NK. triggered by igG, igA, igE. Rapid effector and is dependant on density/ stability of Ab and the affinity for binding FcR. --> Apoptosis. |
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IgG |
- Work horse - long lived - Major ig in human serum - can cross the placenta - facilitates ADCC - major ig in Secondary antibody response |
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igM |
- only ig produced by the fetus - major ig in primary antibody response. |
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igA |
- major ig in EXTERNAL secretions (Sweat, saliva, tears) - defence against infections of GI or respiratory. |
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igE |
- major ig in allergies - after antigen binding, it results in degranulation of mast cells and basophils --> inflammation |
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T cells do not recognize and bind to antigens unless what is present? |
APC - Antigen presenting cells. (MHC --> major histocompatibility complex) |
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All T cells have ______ to hold the TCR in place. |
CD3 |
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Explain MHC I - CD8 T cell cascade. |
- ENDogenous (produced in cell) Found on the surface of NUCLEATED cells. Function is to display pathogenic fragments from within the cell to killer T cells. |
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Explain MHC II - CD4 T cell cascade. |
-EXOgenous Found ONLY on APC. These will ingest pathogens and break them down which the fragments then bind to MHC II and present them for T helper cells. --> releases cytokines. |
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List the steps in T cell differentiation |
1. Null cell presented to cortex 2. immature double positive (contain both CD4 and CD8 3. mature double postive (loses one co receptor to become CD4 OR CD8) |
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Positive selection |
when a t cell can regonize MHC and bing dtrongly and survive. the weak t cells will die |
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Negative selection |
when a t cell can weakly bind and will survive. if it binds strongly it will be marked for death. - process filters in cells that have "Self tolerance" |
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Naive T cells |
T lymphocytes that have not encountered an antigen yet |
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Effector T cells |
T lymphocytes that have been activated by an antigen and is differentiated to elicit defence response. |
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Naive mature T cells require 2 signals to fully activate which are? |
1. Specific 2. Co-stimulatory (Non- specific) **if there is no co-stimulatory then T cell will undergo deletion or anergy. |
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Do effector T cells need the 2nd signal to activate? |
No. |
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When does peripheral tolerance develop? |
when the 2nd signal is missing |
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CD4 differentiates into what 4 subtypes? |
Th1, Th2, Th17, Treg |
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Cytokines can act in 3 ways which are? |
Autocrine Paracrine Endocrine (most common action) - travels to DISTANT cells. |
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cytokines |
produced by cells of innate and aquired immunity. initiate actions by binding to membrane bound receptors. require de novo synthesis and only produced when needed - not always available |
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TNF |
From LPS activated macrophages. is present after a bacterial infection and macrophage senses it. TNF can produce IL 1 AND IL 6 - plays a role in increase of pain |
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IL - 1 |
- from LPS - inhibits joint repair in RA therefore need its inhibitory form --> ILra ILra will bind but not act (just inhibits IL-1 |
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IL - 6 |
- from endothelial and macrophages - liver - synthesis of acute proteins "marker" |
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lymphoid and myeloid cancers can be seen with the overproduction of what? |
IL - 6 |
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"fake" surface receptors |
(deceptors) - bind cytokines without activating the cell. |
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soluble receptor |
neutralize active cytokines |
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receptor antagonist |
may block the action of an active cytokine |
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TH1 produces.... |
IFN |
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TH2 produces... |
IL 4 and IL5 |
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Th1 principle function |
to regulate intracellular cell-mediated immunity. contribute to pathogenesis of autoimmune diseases like RA, crohns |
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Th2 principle function |
to regulate extracellular humoral-mediated immunity. but promote allergic and anti helminth responses. |
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HPA axis |
major part of neuroendocrine system that controls reactions to stress, regulates body processes like digestion and immune system. |
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Neurogenic inflammation |
when neuropeptides are released in response to sympathetic nerve stimulation which cause local inflamation in tissues. |
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Ach ... |
produced by vagus nerve and can cuppress inflammatory reaction = anti inflammatory |
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fever caused by |
TNF and IL1beta because they affect PG2 which causes fever. |
