week12C2 : host defenses Flashcards
***the MAC causes lysis of ______ and has no effect on ____
gram - and as no effect on gram positive
____ are often called polymorphonuclear leucocytes
granulocytes
what are the granules in the granulocytes
small endosomes and lysosomes containing hydrolytic enzymes
where are located the oxidative enzymes in the granulocytes
in the phagosomes.
** what are the two cells that carry primarly the phagocytosis
the neutrophiles (granulocytes) and macrophages (monocytes)
what is the protein of the MAC responsible for the binding with the membrane
the C7
what are the important enzymes of the ROS
myeloperoxidases, NADPH oxidase and V-type ATPase
what are the mechanisms in the second line of defense
- inflammation
- complement system
- phagocytes
what is the role of the complement system
induces the lysis in some of the gram - bacteria.
the ___ are more rapid for the phagocytosis
neutrophiles
which protein of the complement system is involved in the inflammation (histamine by mast cells)
the C3a
what is the role of the C3a blood protein
to trigger the release of histamine by the mast cells to increase the permeability of the blood vessels
what is the role of the C5a in the inflammation
to attract phagocytes to infected tissues
What is diapedesis ?
the passage of white blood cells into the cell walls .
what is the name of a fever producing molecule
a pyrogen
what is the tmeperature range of a fever ?
37 (normal) to 44 (death)
what are the leukocytes that senses the endotoxin lipid A
the macrophages
what cells produces a pyrogen
the macrophage, produces the interleukine-1 (cytokin)
what is the effect of the release of cytokines by macrophages?
fever and activation of phagocytes and other cells.
which one of those defenses is not part of the innate system :
- complement system
- fever
- antimicrobial proteins
- phagocytes
- lymphoid precursor cells
- lymphoid cells (contain the T cells and the B cells)
*** what is the trigger of the adaptive defense system
foreign antigens
define what is tolerance in regards to the immune cells
the receptor for the antigene is generated during the development of the T and B cells
what is the role of the T helper cells
to activate the B cells and the macrophages and mediate inflammation
what is the role of the cytotoxic T cell
to kill the host cells that display a foreign antigen
What is the role of the APC
antigen presenting cells to the T cells. The Th cell will become acitvated and produce interleukin 2 and produces inflammation
What is the most common APC
dendritic cells
where are located the T and B cells
in the lymph nodes
Which one of T cells recognize the MHCI receptor on the APC
cytotoxic T cell
Which one of the T cells recognize the MHCII on the APC
the T helper cell
what does MHC stands for
major histocompability complex (MHC)
***what are the type of cells that have the MHCII
The APCs and the B cells. Can’t be found in other cells.
what are the main type of professional APC
macrophages, dendritic cells and B cells
**what are the cells that express the MHCI
all cells that have been infected (viruse or intracell pathogens. The antigen comes from the inside.
what is the origin of the antigens in the case of B cells and APC cells presenting the MHCII
the antigens come from the phagocytosis of a microorganisms.
what does the Tc cells release to kill the cells that have the antigen on the MHCI complex
granzymes and perforins.
____ (Tc or Th) are very effective in the infection by viruses and intracellular pathogens
Tc
What are angry killer cells
activated macrophages that have an increased phagocytic activity and that produces much higher levels of hydrolytic enzymes
how are the B cells activated?
by the release of cytokines by the Th cells previously activated by APC cells in response to the presenting of antigen on the MHCII complex on the B cell
what happens when a B cell is activated by a Th cell
differnetiation into plasma cells (makes more antibodies) and production of memory cells (expression of the antibody at it’s surface)
what are the two region of the antibodies
Fab : antigen binding region that is highly variable
Fc : macrophage receptor binding region that is constant
what is the other name of the antibodies
immunoglobulins
what is the major circulating antibody
IgG
T or F : the antibodies are only part of the adaptive defense system
false, can be part of the innate because it can help in the activation of the complement system
what is the antibody found in primarly in mucous and extracellular secretory body fluids
IgA
What is the antibody that is the first to appear and help in the early complement activation
IgM
What is the antibody that is the least abbundant and has the major role in food allergies
IgE
How can antibodies help in neutralizing the toxins
they bind the toxins and prevent it to come into contact with cells
What are opsonins?
any molecules are increase the phagocytosis
T or F : the antibodies acts as opsonins
true, opsonin = molecule that increase the phagocytosis
which one of the antibody is implicated in the primary response
IgM
which one of the antibody is implicated in the secondary response
IgG
what are the two types of adaptive (acquired) immunity
active and passive
what is the passive acquired immunity
involves the acquisition of antibodies or antigen reactive T cell (by milk from mother for natural or by injection of immune animal serum is artificial)
what is the active acquired immunity
involves the production of memory cells in response to antigenic stimulus
