Flashcards in Cells and Tissues of the Adaptive Immune System Deck (48):
1
what are the primary lymphoid organs?
thymus and bone marrow
2
what are the secondary lymphoid organs?
spleen, lymph nodes, and mucosa-associated lymphoid tissue
3
where do all blood cells develop from ?
common pluripotent stem cells
4
where do T cells proliferate, differentiate, and complete their maturation?
the thymus
5
where do B cells proliferate, differentiate, and complete their maturation?
bone marrow
6
what kind of receptors are localized on the surface of T and B cells?
Ag - specific receptors
7
explain the structure of Ag-specific receptors on T and B cells.
the structure varies from one cell to another but they are all identical on a single cell.
8
if naive lymphocytes do not recognize Ag, how long does it take them to die?
1 to 3 months
9
What another name for treg cells?
hassall's corpuscle
10
cytokines IL-1 IL-2 IL-6 and IL-7 play an important role in the development of which cell?
T cells
11
what do naive cells refer to?
B cells or T cells that have not yet been exposed to Ag
12
where are naive cells maintain ?
in the periphery without proliferating
13
what are the two different kinds of T cells developed? what do they express
T helper cells which express CD4 and provide help for B cell growth and differentiation
cytotoxic T lymphocytes (CTLs) express CD8 and recognize and kill virus-infected cells
14
where to functionally mature T cells migrate to ?
to secondary lymphoid tissues to mediate protection
15
at birth what color is bone marrow?
all red
16
what color is bone marrow in adults?
half red and half yellow
17
where does differentiation into B cells occur before and after birth?
before in fetal liver
after birth in thymus
18
lymphocytes continuously circulate reaching various parts of the body except which few?
eye, brain, and testicles
19
in search of foreign Ags, lymphocytes enter the secondary lymphoid organs vis a specialized endothelium of post capillary venues called what?
high endothelium venules HEV
20
cells of HEV express high levels of ______ that serve as what?
adhesion molecules
"homing" receptors for lymphocytes
21
Lymphocytes transmigrate by what?
by diapedesis into the tissue in response to chemokine
22
Lymphocytes reenter the circulation via what?
via efferent lymph vessels that merge into the thoracic duct
23
lymphocytes may be activated by foreign Ags in these secondary lymphoid tissue, but if not, and they're still naive lymphocytes, they will return to the blood by what?
lymphatic drainage
24
Explain the steps in activation of B cells.
naive B cells migrate into the secondary lymphoid tissue where they look for and respond to soluble foreign Ags
Ag activated b cell proliferate in germinal centers and mature into memory cells or into plasma cells
plasma cells is terminally differentiated b cells which produce and secrete large amount of Abs
in the spleen, Ag activated b cells primarily produce Abs against microbial in the blood
25
in the spleen, t cell and b cell zones makes up the _____ pulp.
white pulp
26
Explain the steps in activation of T cells.
in search of foreign Ag, naive T cells migrate into secondary lymphoid organs such as lymph nodes
t cells which were activated by Ags differentiate into effector or memory t cells
some effector and memory t cells migrate back into the peripheral sites of infection
some activated and differentiated T cells remain in the LNs and help AG activated B cells to become "an Ab factory"
27
the naive cells enter the lymph node through what?
an artery leaving the circulation by moving across the HEV
28
B and t cells migrate to different zones of the lymph node directed by what?
by chemokines that are produced in these areas by stroll cells
29
Das pick up Ags from the sites of Ag entry and enter through what?
through afferent lymphatic vessels
30
where do Das migrate in the lymph node?
to the T cell rich areas of the node
31
what type of follicles can be found in the lymph nodes?
primary and secondary
32
in the absence of Ag stimulation, explain the follicles in the lymph nodes.
follicles are primary follicles, composed of naive b cells or recirculating memory B cells
33
with Ag stimulation, b cells proliferate and differentiate converting the primary follicle into what?
into a secondary follicle or germinal center
34
Professional APCs are:
dendritic cells
tissue macrophages
b cells
35
Do T cells of B cells need APC?
T cells
36
What are APCs?
they are cells that capture, process, and display Ags to T lymphocytes and provide signals that stimulate the proliferation and differentiation of the lymphocytes
37
Which cells provide a link between innate and adaptive immunity?
DCs and tissue Macrophages
38
Das are part of the _____ lineage.
myeloid
39
Das can be broadly divided to what?
classical Das, myeloid (mDCs) and plasmacytoid DCs (pDCs)
40
what are DCs derived from?
monocytes
41
classical Das, pDC and langerhan's cells (LCs) in epidermis of the skin, develop directly from what?
from stem cells
42
what do DCs use to acquire Ags?
use phagocytosis, receptor-mediated endocytosis, and pinocytosis
43
activated DCS also secrete what?
cytokines
44
where do classical Das reside?
in skin, mucosa, and organ parenchyma
45
upon activation by microbes, classical Das migrate to lymph nodes where they display what to T lymphocytes?
display microbial protein Ags to T lymphocytes
46
plasmacytoid DCs are early cellular responders to what?
to viral infection
47
what do plasmacytoid DCs recognize and produce?
recognize nucleic acids of intracellular viruses
produce soluble interferons a.k.a. IFN-alpha/beta
48