T cells Flashcards
Describe the journey of T cells from thymus to Peyer’s patches.
Thymus –> accumulate in paracortex of lymph node –> periarteriolar lymphoid sheaths of spleen –> interfollicular areas of peyer’s patches
T cells account for __ % and B cells account for __% of blood lymphocytes.
NK cells account for __% of blood lymphocytes.
T cells = 60-80%; B cells = 10-40%; NK cells = 5-10%
Where do B cells originate and where do they mature?
- originate in bone marrow)
- Matures in peyer’s patches or bone marrow before migrating out to secondary lymphoid organs.
B cell predominate what part of the lymph node?
What part of Peyer’s patches and what part of spleen?
cortex of lymph node, follicles within Peyer’s patches and spleen, marginal zone of white pulp of spleen
Where are B cells distributed? and how does it compare to T cell distribution?
B cells: Lymph node cortiex, splenic follicles
T cells: lymph node paracortex, spleen periarteriolar sheath
T/F: B cells circulate in the bloodstream.
F; T cells circulate, B cells do not
List the important surface receptors of T cells
CD2
CD3
CD4
CD8
What’s another name for CD2?
LFA-2
cell adherence molecule whose ligands are cd58 (nonrodent) and CD48 (rodent)
found on T and B cells
T/F: CD4 is found on both B and T cells
F: only found on T cells
CD4 is a receptor for MHC II molecules that plays a key role in recognition of processed antigen by Th cells. Expressed on Th cells, thymocytes, monocytes
List mitogens for B and T cells
B cells: pokeweed, lipopolysaccharide
T cells: Phytohemagglutinin, Concanavalin A, BCG vaccine, pokeweed
T/F: B cells recognize free foreign proteins and T cells recognize processed proteins in MHC antigens
T
What’s the difference between alpha/beta TCR and gamma/delta TCR?
Alpha/beta TCR: uses paired alpha and beta peptide chains vs gamma and delta peptide chains
(add to this)
What’s the difference between BCR and TCR in terms of their
- TCR: 2 subpopulations (alpha/beta and gamma/delta); CD3 found on all T cells
- BCR: 5 different heavy chains (gamma, mu, alpha, episilon, delta); BCRs are shed in large amounts into tissue fluid and blood as antibodies
How do NK cell receptors differ from B and TCR?
NK cells have receptors that can bind molecules expressed on healthy normal cells but not on diseased, abnormal cells. NK cells recognize and kill target cells that fail to express these surface molecules
What is the CD name given to signaling transducing proteins in the TCR? Which is for all T cells vs Th vs CTL cells?
CD3 (all T cells)
CD4 on Th cells only
CD8 for CTL
CD8 and CD4 are the receptors for MHC I and II molecules respectively. Neither CD4 or CD8 are expressed on NK cells
CD__ is expressed in large amounts on all three lymphocyte populations,
CD45
What is CD45?
a family of tyrosine phosphatases, some of which are required for signaling through TCR. Multiple isoforms are generated by alternative splicing of 3 exons. Found on all hematopoietic cells except RBCs.
What’s the other name for the BCR signal-transducing peptide, Ig-alpha and Ig-beta?
CD79a, CD79b
Committed lymphoid CD__ stem cells migrate from bone marrow to ___ of thymus
Committed lymphoid CD7+ stem cells migrate from bone marrow to cortex of thymus
Clusters of differentiation refer to what?
Clusters of differentiation denote a glycoprotein of specific function.
What mineral is essential for T cell development, and what is the peptide within which it is contained?
- Zinc is an essential mineral for the development of T cells. Consequently, zinc-deficient animals have defective cell-mediated immune responses
- Thymulin = a zinc-containing peptide
secreted by the thymic epithelial cells;
Thymic Stromal Lymphopoietin (TSLP) is expressed by _____
Hassall’s corpuscles
play a functional
role in regulating thymic activity since they express a growth factor called thymic stromal lymphopoietin (TSLP).
Why are bursectomized birds more susceptible to salmenollosis but not mycobacterium?
Bursectomized
birds have very low levels of antibodies in their blood, and
antibody-producing cells disappear from lymphoid organs.
However, they still possess circulating lymphocytes and can
reject foreign skin grafts. Thus, bursectomy has little effect on
the cell-mediated immune response. Bursectomized birds are
more susceptible than normal to leptospirosis and salmonellosis
but not to intracellular bacteria such as Mycobacterium
avium.
Binding of circulating lymphocytes to ligands on endothelial cells in high endothelial venules is brought about mainly by
___ binding to __ and ___.
Binding of circulating lymphocytes to ligands on endothelial cells in high endothelial venules is brought about mainly by
L-selectin binding to GlyCAM-1 and CD34.
Pig lymphocytes are largely confined to Bloodstream, lympho node, spleen, or cornea
bloodstream; not thoracic duct like other mammals
Although the primary immune response to intravenously injected antigen takes place in ____, the
antibodies produced in a secondary response are largely produced in the ___.
Although the primary immune response to intravenously injected antigen takes place in LYMPH NODE OR SPLEEN , the antibodies produced in a secondary response are largely produced in
the BONE MARROW
The ___pulp of the spleen contains both B and T cells, which accumulate in their specific zones under the influence of chemokines.
The ___ consist largely of T
cells. Within these, the T cells interact with dendritic cells and passing B cells.
The B cell areas, in contrast, consist of round primary follicles scattered through the sheaths. These follicles are sites where____ occur
The WHITE pulp contains both B and T cells, which accumulate in their specific zones under the influence of chemokines.
The periarteriolar lymphoid sheaths consist largely of T
cells. Within these, the T cells interact with dendritic cells and passing B cells.
The B cell areas, in contrast, consist of round primary follicles scattered through the sheaths. These follicles are sites where __germinal center formation, clonal expansion, isotype switching, and somatic hypermutation__ occur
During a primary immune response, antibodies are produced in ___ and __.
Spleen and lymph nodes.
Toward the end of that response,
memory cells leave the spleen and colonize the bone marrow. When a second dose of an antigen is given, the bone marrow produces very large quantities of antibody and is the major source of antibodies in adult rodents. Up to 70% of the antibody to some antigens may be produced by cells in the bone
marrow
