Lymphoid Structures & Lymphocytes Flashcards
A secondary lyphoid organ that has many afferents, 1 or more efferents. Encapsulated, with trabeculae.
Lymph Node
Site of B cell localization and proliferation
Follice
Where do histiocytes reside?
Medulla
Houses T cells
Paracortex
Not well developed in patients with DiGeorge Syndrome
Paracortex
Enlarges in Mononucleosis
Paracortex
Head and Neck Drain into what LN cluster?
Cervical
Lungs drain into which LN?
Hilar
Trachea and Esophagus drain into which LN?
Mediastinal
Upper limb, breast, skin above umbilicus drain into which LN?
Axillary
Liver, Stomach, Spleen, Pancreas, Upper duodenum drain into whcih LN?
Celiac
Lower duodenum, jejunum, ileum, colon to splenic flexure drain into which LN?
Superior Mesenteric
Colon from splenic flexure to upper rectum which drain into which LN?
Internal Iliac
Testes, Ovaries, Kidneys, Uterus drain into which LN?
Para-aortic
Anal canal (below pectinate line), skin below umbilicus (except popliteal area) drain into which LN?
Superficial Inguinal
Dorsolateral foot adn posterior calf drain into which LN?
Popliteal
Right Lymphatic Duct drains…
right side of body above diaphragm and heart and lungs
Where does Thoracic Duct drain into?
Left Subclavian and internal jugular veins
In the spleen, where are T cells found?
Periarterial lymphatic sheath, in white pulp of spleen
In spleen, where are B cells found?
In follicles wihtin the white pulp of the spleen
What do you find in the marginal zone of the spleen?
APCs and specialized b cells where APCs present blood-borne antigens
Splenic dysfunction will acuse decrease of what immunoglobulin and complement?
IgM and C3b
What type of organisms will a patient be more susceptible to post-splenectomy?
Encapsulated: S. pneumonia, Hib, N. meningitidis, E. coli, Salmonella, Klebsiella pneumonia, group B strep
Site of T cell differentiation and maturation.
Thymus
Which pharyngeal pouch does the thymus come from?
3rd
Where are immature T cells found?
Cortex of thymus
Where are mature T cells found?
Medulla of thymus
Where do you find Hassall corpuscles?
Medulla of thymus
Can get resistance to innate immunity by
mutations in germline
Can get resistance to adaptive immunity by
variation through VDJ recombination during lymphocyte development
Innate immunity response time to pathogens
minutes to hours
Adaptive immunity response to pathogens
highly specific, refined over time
memory response can be rapid and robust
pattern recognition receptors that recognize pathogen-associated molecular patterns (PAMPs)
Toll-like receptors, innate immunity
LPS (gram negative bacteria), flagellin (bacteria), ssRNA (viruses) are examples of what?
pathogen-associated molecular patterns
Chromosome for MHC I and II
6
HLA-A, HLA-B, HLA-C are loci associated with which MHC?
MHC I
Cells MHC I is presented on
all nucleated cells
What presents endogenously synthesized antigens (viral) ?
MHC I
What presents exogenously synthesized proteins (bacteria and viral capsids)?
MHC II
What uses a TAP peptide transporter for antigen loading?
MHC I
Antigen loaded following a release of invariant chain in an acidified endosome
MHC II
Beta-2 microglobulin
MHC I
Loci for this product are HLA-DR, HLA-DP, HLA-DQ
MHC II
only expressed on APCs
MHC II
HLA - A3 associated disease
hemochromatosis
Which HLA subtype is associated with psoriatic arthritis, ankylosing spondylitis, arthritis of inflammatory bowel disease, reactive arthritis (Reiter)?
HLA- B27
HLA subtype associated with Celiac Disease
DQ2/DQ8
HLA subtype associated with MS, hay fever, SLE, Goodpasture
DR2
HLA subtype associated with DM type 1, SLE, Graves disease
DR3
HLA-DR4 is associated with what diseases?
RA and DM type 1
HLA-DR5 is associated with what diseases?
Pernicious anemia, vitamin B12 deficiency, Hashimoto thyroiditis
2 things released from NK cells to induce apoptosis
perforin and granzymes
Express CD56
NK cells
IL-2, 12, IFN-beta & alpha enhance activity of what cell?
NK cell
When are NK cells induced to kill?
when exposed to a nonspecific activation signal on target cell and/or to an absence of class I MHC on target cell surface
MoA of killing antibody-dependent cell-mediated cytotoxicity
NK cell CD16 binds Fc region of bound Ig, activating the NK cell
What cell undergoes somatic hypermutation to optimize antigen specificity?
B-cell
Cell that help B cells make antibody and produce cytokines to activate other cells of immune system
CD4+ T cell
Kill virus infected cells directly
CD8+ T cells
Positive selection occurs where?
Thymic cortex
T cells expressing TCRs capable ot binding surface cell MHC molecules SURVIVE
positive selection
Negative selection occurs where?
Medulla of thymus
T cells expressing TCR with high affinity for self-Ags undergo apoptosis
Negative Selection
Helper t cell secretes IL-12 to actvate what?
Th1 cell
Helper T cell secretes IL-4 to activate what?
Th2 cell
Helper T cell secretes TGF-beta + IL-16 to activate what?
Th17 cell
Helper T cell secretes TGF-beta to activate what cell?
T-reg cell
Costimulatory signal for naive T cell activation include interaction between
B7 and CD28
What receptor on the B cell will bind to this ligand on Th cell for CD4+ cell to secrete cytokines?
CD40 receptor on B cell binds CD40 ligand
Th1 is inhibited by these products from Th2
IL-4 and IL-10
Th1 secretes what cytokine(s)?
IFN-gamma (stimulates macrophages & inactivates Th2)
Activates macrophages and cytotoxic T cells
Th1
Macrophages release ___ to stimulate T cells to differentiate into Th1
IL-12
Recruits eosinophils for parasite defense and promotoes IgE production by B cells.
Th2
This cell is inhibited by IFN-gamma
Th2
Granzyme B
serine protease from cytotoxic T cells that activate apoptsis inside target cell
Granulysin
from cytotoxic T cell, antimicrobial, induces apoptosis
Regulatory T cells
suppress CD4 and CD8 T cells
Cell surface markers for T-reg cell
CD3, 4, 25, and TF FOXP3
There’s a what in my boot?
A snake in my boot!!!
