Immunology Flashcards
Primary lymphoid organs (2):
Thymus
Bone marrow
Site of B cell localization in a lymph node:
Follicle
Where the T cells in a lymph node are located:
Paracortex
This is right next to the follicle
Portion of a lymph node that becomes hugely enlarged in a robust cellular immune response:
Paracortex
Why do lymph nodes not enlarge in patients with DiGeorge?
They have no T cells. The paracortex, or T cell region, is what enlarges when a lymph node swells.
Where are the high endothelial venules of lymph nodes located?
Paracortex
T and B cells enter here
The primary lymph node drainage site for the upper limb and lateral breast:
Axillary
The primary lymph node drainage site for the stomach:
Celiac nodes
The primary lymph node drainage site for the duodenum and jejunum:
Superior mesenteric nodes
The primary lymph node drainage site for the sigmoid colon:
Colic nodes, which drain to inferior mesenteric nodes
The primary lymph node drainage site for the rectum above the pectinate line:
Internal iliac nodes
The primary lymph node drainage site for the anal canal below the pectinate line:
Superficial inguinal nodes
The primary lymph node drainage site for the testes:
Superficial and deep para-aortic plexes
The primary lymph node drainage site for the scrotum:
Superficial inguinal nodes
What does the right lymphatic duct drain? What happens if you obstruct this duct or it gets damaged?
The right arm, chest, and right half of the head.
Damage -> non-pitting edema of RUE.
Where does the thoracic duct empty?
Jx of L subclavian and IJ
Three ways you can become asplenic:
Sickle cell
Trauma
Surgery (eg for spherocytosis)
Where are T cells in the spleen?
They live in the peri-arteriolar lymphatic sheath (PALS).
Remember, P for Paracortex (LN) and PALS (spleen).
Where are B cells found in the spleen?
In the follicles in the white pulp.
T/F: T cells are found in the red pulp of the spleen.
F. PALS is where they live, this is in the white pulp.
Post-splenectomy, 3 buzzwords:
Howell-Jolly bodies
Target cells
Thrombocytosis
Asplenia renders someone vulnerable to what organisms? Which do we have vaccines for?
Encapsulated ones. Even Some Killers Have Pretty Nice Capsules: E. coli Strep pneumo * Klebsiella H. influenzae * Pseudomonas Neisseria (mening. and gonococcal *) Cryptococcus
From what embryonic structure does the thymus come? What other structure develops from this origin?
The 3rd branchial pouch. Inferior parathyroids develop with the thymus.
In the thymus, where do mature T cells live? What kind of selection are they undergoing here?
Mature T cells live in the Medulla of the thymus, here they are undergoing (-) selection (learning not to kill the host cells).
In the thymus, where do immature T cells live? What kind of selection are they going through here?
Immature T cells live in the cortex.
Mature live in the Medulla.
They are undergoing (+) selection and learning to talk MHC.
The HLA subtypes associated with MHC I:
HLA-A
HLA-B
HLA-C
To what co-receptor does MHC I bind? MHC II?
CD8
CD4
Which cells express MHC I?
Which cells express MHC II?
MHC I is on the surface of all nucleated cells.
MHC II is only on APCs (macs, B cells, dendritic cells).
Which HLA subtypes are associated with MHC II?
Dr. is going to DQ to get a DrPepper.
HLA-DR
HLA-DQ
HLA-DP
Which MHC molecule needs to travel with b2 microglobulin to be displayed?
MHC I
HLA associated with hemochromatosis:
HLA-A3
HLA associated with the seronegative arthropathies:
Can you name 4 of these illnesses?
HLA-B27
Ank. spondylitis, Reiters / reactive arthritis, IBD, psoriatic arthritis
HLA subtypes associated with celiac disease:
HLA-DQ2 / DQ8
HLA subtypes associated with MS, hay fever, SLE, and Goodpasture’s
HLA-DR2
HLA associated with type 1 diabetes (2):
HLA-DR3 / DR4
HLA associated with pernicious anemia:
HLA-DR5
Two surface markers for NK cells:
CD-16
CD-56
T/F: NK cells require T cell help to induce apoptosis of infected / cancerous cells:
F. They use perforin and granzymes on their own, respond to coded antigen and absence of MHC I.
Cytokines that enhance NK cell activity:
IL-2
IL-12
IFN-b
IFN-a
NK cells secrete this cytokine to activate macrophages:
IFN-g
What does CD-16 do and what cell types carry it?
Killers have it (macs, neut, monos, NK).
It binds the constant region of Ab and targets the Ab bearing cell for destruction.
Cell type that mediates hyperacute organ rejection:
B cells
TH1 cells secrete two main stimulatory cytokines. What do they do?
IFN-g calls out to macrophages
IFN-g also inhibits other T cells from going down the TH2 path
IL-2 stimulates T cells, NK cells
This cytokine is secreted by TH2 cells to inhibit TH1 cell development:
IL-10
These two cytokines are secreted by TH2 cells and stimulate B cells:
IL-4
IL-5
This interleukin drives TH1 development, where this interleukin drives TH2 development:
IL-12 drives TH1
IL-4 drives TH2
Which cell is the only cell that can activate a naive T cell?
Dendritic cell
Three APCs:
Dendritic cell
Macrophage
B cell
A naive T cell requires MHC + antigen + appropriate co-stimulation. What are these costimulatory molecules? A B cell requires a different pair of costimulatory moleucles, what are they?
CD28 on the T cell
CD80 = CD86 = B7 on the dendritic cell
CD40 on the B cell
CD40 ligand on the T cell
The macrophage activating cytokine:
IFN-g
Two cytokines that inhibit TH1 cells:
IL-4
IL-10
(both from TH2 cells)
Cytokine TH1 cells secrete that inhibits TH2 cells:
IFN-g
Four buzz-words for cytotoxic T cell killing mechanisms:
Perforin (enters cell)
Granzyme (serine protease)
Granulysin
FAS ligand (+ FAS receptor on host cells)
Three things expressed on the surface of regulatory T cells?
CD3
CD4
CD25
Where does complement bind an Ab?
The Fc, CH2 region (just below the hinge).
Gene products responsible for VDJ recombination. What do these proteins recognize?
RAG1 & RAG2
Recognize recombination signal sequences = RSSs
There are two light chains in human Ab:
What is the normal ratio in humans?
kappa
lambda
2K:1L
Most abundant Ab:
IgG
Crosses the placenta:
IgG
Life expectancy of a maternal Ab in a baby:
~21d
Ab that is a dimer when secreted:
IgA
Ab that is found in colostrum:
IgA
Ab that mediates type I hypersensitivity:
IgE
Ab that fixes complement (2):
IgG, IgM
This Ab prevents attachment of bacteria to mucous membranes:
T/F: It fixes complement.
IgA
F. No.
Two antibodies involved in the classic pathway of complement activation:
IgG
IgM
Triggers for each of the following complement pathways:
- Classic
- Lectin
- Alternative
- Classic = Ab mediated (IgG, IgM)
- Leptin = mannose binding protein made by the liver
- Alternative = molecules on the microbe
Complement protein for neutrophil chemotaxis:
Two other neutrophil chemotactic proteins:
C5a
IL-8, leukotriene B4
Complement proteins (2) responsible for anaphylaxis:
C3a, C5a for Anaphylaxis
Complement proteins involved in forming the membrane attack complex:
C5b-9
Two complement proteins that help prevent complement from activating on self cells:
Decay-accelarating factor (DAF)
C1 esterase inhibitor = C1 esterase = C1 inhibitor
What is C1 esterase?
An inhibitor of the complement cascade, prevents host cells from being attacked by complement.