Test 4 Study Guide Part 6 Flashcards
Macrophages:
- Are called what in the bloodstream?
- What do they do in inflammation?
- Are called what in the bloodstream?
- What do they do in inflammation?
They ingest microrganism and ECM fragments
Excrete Nitric oxide (vasodilator, destroy bacteria)
Engulf remains of neutrophils
Phagocytosis of apoptotic neutrophils causes:
Macrophages to release growth factors and agents to stop inflammation and support repair.
NO has to functions:
Antibacterial
Vasodilator
B-lymphocyte involvement in inflammation:
Produce antibodies specific to antigenic determinants
Binding of antibodies to antigen:
Enhances non-specific response (due to antigen antibody complexes activating compliment system)
Act as opsonins
Process by which an organism is marked for phagocytosis
Opsinisation:
Opsonins:
- name two:
- what do they do?
- name two: Complement proteins Antibodies - what do they do? mark for phagocytosis, they help make bridges between pathogen and immune cell. helps hold organism in place and allow it to be easier to phagocytose
What promotes pain in inflammation?
How does aspirin inhibit it?
Prostaglandin E2
Inhibition of cyclooxygenase stops prostaglandin production, reducing pain
COX-1, COX-2 stand for what?
What do that do?
What inhibits them?
Cycloxygenase-1, Cycloxygenase-2
Make prostaglandins
NSAIDs (including aspirin)
If infection from inflammation continues, what will be produced to promote fever?
Interluekin-1 (endogenous pyrogen)
Chronic inflammation can lead to:
- Pulmonary disease:
- Diabetes II:
- Autoimmune disease:
- Arthritis:
- Neurological disease:
- Alzheimer:
- Cardiovascular disease:
- Cancer:
Are B and T cells visually distinguishable?
No
Where does B-cell activation usually occur?
in the germinal center of a secondary lymphatic organ.
What does an activated B-cell do?
Replicate.
Activated b-cell progeny will become either:
Memory cell
Plasma cell
Plasma cells produce how many antibodies a second?
2000
Antibodies:
- Alternative names:
- Mechanism:
- Alternative names: Gamma globulins Immunoglobulins - Mechanism: mark targets for destruction
IgG:
80% of antibody in plasma
Activates complement
Can cross placenta and leave the blood easily
IgA:
- two forms:
- Located
- Does not:
- two forms: monomer dimer - Located In body secretions (milk, saliva) - Does not: Activate compliment Enter tissues
IgE:
Important in allergic (immediate hypersensitivity) reactions
for antibodies…
Stock the Y is called:
top of the Y is called:
Which region varies in order to bind the antigen?
Crystallizable fragment (Fc)
Antigen-binding fragment (Fab)
Fab
Antibody receptors:
Found on B-cells
Very specific to one antigen
Antigen can be a carbohydrate or protein
B-cells when activated will produce only one antibody
Two pathways for activation of compliment system:
Classical pathway (faster. antibody-antigen complex by IgG or IgM) Alternative pathway (bind to target on pathogen surface)
complement proteins attach to the cell membrane and destroy the victim cell.
Compliment fixation:
Which compliment proteins stimulate mast cells to excrete histamine?
Which serve as chemokines macrophages for macrophages, neutrophils, monocytes and eosnophils?
C3a and C5a
C3a and C5a (does both)
Membrane attack complex:
- Formed by:
- Mechanism of pathogen destruction:
- Formed by:
C5b, C6, C7, C8, C9 - Mechanism of pathogen destruction:
membrane attack complex is a pore in the cell. It causes osmotic influx of water, which lyses the pathogen
What causes destruction of RBCs in a transfusion reaction and in hemolytic disease of the newborn?
Antigen-antibody complex -> Compliment fixation (compliment proteins kill them)
the compliment fragments:
- direct affects:
- Affect as a result of other activations:
- direct affects:
Chemotaxis
Opsinization
Stimulate mast cells to release histamine - Affect as a result of other activations:
Histamine release -> vasodilation of blood vessels, increased permeability -> more phagocytic cells come -> edema results from leakage of plasma protein into surrounding fluid
Three types of effector T cells:
Cytotoxic (killer) T cells
Memory T cells
Regulatory T cells
Mycobacterium tuberculosis is an:
- Is targeted by:
Intracellular bacterium
Cell-mediated immunity
Cytotoxic (killer) T cells:
- Surface molecule:
- Function:
- Surface molecule:
CD8 - Function:
Cell-mediated destruction of cells with intracellular parasites (requires physical contact)
Cell-mediated destruction:
Process requiring physical proximity by which a cell kills another cell.
Perforin makes whole -> granzymes enter -> capsases activated (cell undergoes apoptosis and dies)
Perforins:
Produced by cytotoxic T-cells, make a whole through which granzymes can enter.
Granzymes:
Produced by cytotoxic T-cells, enter through perforin induced wholes, activate caspases
Caspases:
Enzymes involved in the events of cell death. Activated by granzymes during cell-mediated destruction to cause a cell to kill itself.
- Test: press of four tines into skin coated in acellular extract, old tuberculin if HARD (inflammation) in 48-72 hours it is positive for tuberculosis
Tuberculin time test:
- Test:
- Test:
Injection of purified protein derivative by needle
if HARD (inflammation) in 48-72 hours it is positive for tuberculosis
Mantoux test:
- Test:
Tuberculin time test and Mantoux test:
- Predominant Immune cells:
- Example of:
- Predominant Immune cell:
T- cell, cell mediated response - Example of:
delayed hypersensitivity
Helper T cells:
- Surface molecule:
- Function:
- Which virus targets this specifically?
- Surface molecule:
CD4 - Function:
Improve B cell differentiation into plasma cells
enhance ability of cytotoxic lymphocytes to mount cell-mediated immune response - Which virus targets this specifically?
HIV is specific to CD4
Helper T cells perform their function how?
Secrete lymphokines (type of cytokine). E.G. interleukin-2 is a cytokine which aids killer T lymphocyte response
Regulatory T cells (Ts):
- Function:
- How?
- Function:
Immune suppression to prevent inappropriate immune responses - How?
Not completely understood.
Requires close proximity (maybe physical contact) between Ts and target.
Cytokines necessary
What can result from inadequate regulatory T cell function?
Autoimmune disease
Allergies
Lymphokine:
Autocrine (type of cytokine that effect the cell type which excretes them) of a lymphocyte.
Naming conventions for lymphokines:
Interleukin-#, where numbers are assigned in chronological order after the sequence of amino acids is known
Interleukin-1 (IL-1):
Induces proliferation and activation of T-lymphocytes
Endogenous Pyrogen
Interleukin-2 (IL-2):
Induces proliferation of activated of T-lymphocytes
Interleukin-4 (IL-4):
Stimulates proliferation of activated B cells
promotes IgE antibody production
increases cytotoxic t cell activity
Interleukin-5 (IL-5):
induces activation of cytotoxic t cell
promotes eosinophil differentiation
Chemokine for eosinophils
T cell receptor proteins for antigens:
Recognize only proteins
Can only bind antigens presented on a MHC (Major histocompatabillity complex) by a antigen presenting cell (often macrophages and dendrites)
What are the dendritic cells of the epidermis:
- How much of the epidermis do they take up?
Langerhans
- How much of the epidermis do they take up?
3 - 5 % of all cells in the epidermis
Why do T-cells only respond to antigens on an MHC?
It’s protective. It means T-cells can only respond against antigen presenting cell approved antigens
How do antigen presenting cells achieve activation of T lymphocytes?
Activated antigen presenting cells migrate through lymphatic vessels, to secondary lymphoid organs.
They produce chemokines to attract T-lymphocytes
Activated T cells make:
Effector T cells first.
Then memory T cells
Tissue Typing:
Identify all histocompatibility antigens being displayed by a cell. If it is displaying radically different things then the host cells are graft rejection is going to go down hard.
Histocompatibility antigens:
A part of the MHC. They are proteins that are found within the cell (either naturally or after phagocytosis by an immune cell), This is the antigen checked by the T cells
Histocompatibility antigens are called what in humans?
Why?
Human leukocyte antigens (HLAs). This is because they used to tissue type WBCs, and so named histocompatibility antigens off of the cell they typed.
These are coded for by a region of genes, known as the major histocompatibility complex located on chromosome 6.
MHC is both a set of genes, the MHC genes, and the molecule produced by these genes when they conglomerate.
True
Class 1 MHC molecules (MHC-1):
- Found on what cells?
- Present what?
- Present by what cells?
All but RBCs (all nucleated) - Present what?
Internal proteins, usually self antigens unless invaded
Class 2 MHC molecules (MHC-2):
- Found on what cells?
- Present what?
- Present to what cells?
- Found on what cells?
Only antigen presenting cells (Macrophages, Dendritic cells, and B cells) - Present what?
Their class-2 MHC molecules together with foreign antigen found by ENDOCYTOSIS - Present to what cells?
T cells
