- something that can bind to the recep
: including eye, nose, l
- largest space of immunity
Where are the pathogens?
Major Concepts
Pathogen: An infectious agent
Extracellular: pathogen that can replicate
outside the cell
• bacteria (c, d), parasites (k, I), fungus (h, i, j)
Intracellular: pathogen that requires cellular
environment to replicate
• bacteria (e, f, g), viruses (a, b)
Mucosal immunity: response mounted at the
mucosal surface
Innate immunity: early phase of host response
to pathogen
Adaptive immunity: response of an antigenspecific lymphocyte to an infection
Antigen: a molecule which can stimulate an
adaptive immune response
Figure 1.3 The Immune System, 3ed. (© Garland Science 2009)
Overall immune response:
-
: innate immunity that can fight the
infection right away
: constantly present
: can be highly variable
: related to lymphocytes, "more adaptive
immunity tailored"
1. 2 central lymphoid organs: where
lymphocytes are formed
- bone marrow : B-cell
- thymus : gives rise to T-cells
(thymocytes!)
2. peripheral lymphoid organs:
- lymph node: where T-cells are activated
- spleen
(less related to generation)
0 allows for the antigens to be brought to the lymphocytes & presented
bone marrow is the site of adult
hematopoiesis (not children)
RBC : carries O2
"precursor of the T-cells"
"precursors of macrophages"
3 granulocytes:
"family of immune
cells"
hematopoeitic stem cells must adhere to stromal cells, signals are provided for growth and identification
- many use fat as a fuel rather than O2
- hypoxic environment around blood vessel
a multi-step
process
: the original cell with the potential to differentiate
1)
Lymphoid forms
B-cell, T-cell, NK
and ILC
2)
many other progenitors can
produce blood cells
: innate immune cells
macro : a lot
phage : to eat
- function: perform
phagocytosis of foreign
pathogens / antigen
presentation
granulocytes:
- release granules to kill foreign
pathogens
- function: antigen
update in peripheral
sites for antigen
presentation
- function: drivers behind
allergy and release histamine
within granules
- accumulation of lipids appear "foamy"
- granules
- many types of macrophages : monocytes in blood, in tissues they become macrophages and express different receptors for activation
: pagocytosis
: an alert for the presence of a
foreign pathogen
: clear extracellular and intracellular pathogens
monocytes = precursors
macrophages are in the tissue
macrophage binds to the pathogen, try to eat it, release of chemokines/cytokines and changes the local environment
- blood vessel causes vasodilation (swelling, redness, heat) and allows for inflammatory cells to migrate into the tissue
- monocytes get recruited to differentiate
chemokine : guides for cell migration to arrive at the correct time
cytokine:
PRRS are expressed
on the outside of the macrophages
- designed to recognize
pathogen patterns
* also rapid cytokine secretion is allowed
granules are packed with toxic proteins & proteases
granules are filled with acid, more dangerous proteases
ANTIGEN PRESENTATION
germinal center indicating acute infection
Congenital Asplenia: Case Study
Colloidal gold (198Au) scan
Mother
Liver
Children
Spleen
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