Immunology 2

Description:	Easier stuff
Category:	USMLE
Created by:	ddecampo on 2009-05-11

Question	Answer
Functions of lymph node	filtration by macrophages, storage and activation of B/T cells, antibody production
Follicle/cortex of lymph node holds. Difference between primary and secondary follicle	B cells. Secondary follicle (germinal ctr) is pale and is a site of active proliferation
Medulla of lymph node consistes of cords and sinuses. What are they composed of? Where do sinuses drain to?	Cords: lymphocytes, plasma cells, Sinuses= macrophages, reticular cells and communicate with efferent lymphatic
Paracortex/deep cortex	Houses T cells; has endothelial venules from which T and B cvells enter. Becaomes enlarged in immmune resposne (viral)
3 functions of the spleen	capture organisms and Ag trapping, site for extramedullary hematopoiesis, reservoir for 1/3 of platelets
Which part of spleen has "barrel hood" basement membrane? Where are macrophages found?	Near basement membrane. Red pulp
Where are T cells and B cells found in the spleen?	T cells = periarterial lymphatic sheath, red pulp, B = follicles in white pulp
Describe what happens in splenic dysfunction?	Decreased IgM (due to abnormal follicles--> decreased complement activation --> decreased c3b opsonization, increased susceptiblity to encapsulated organisms.
What organisms is a patient susceptible during splenic dysfunction?	Encapsulated: S. pneumoniae, H. influenzae, Salmonella
Postsplectomy results in	Howell Jolly bodies, target cells, thrombocytosis
T cells in the thymus are originally from ___. They travel to the thymus and are in immature in the ___.	T cells are mesenchymal in origin (bone marrow), Immature = cortex
Mature T cells are found in the ___ of the thymus, which also contains ____ and ____/	medulla and contains Hassall's corpuscles, reticular epithelial cells
What happens in positive selection? Negative selection	Positive = Recognize MHC or MHC II. Negative APC cells present Ag; those that don't interact undergo apoptosis.
In cortex, before positive selection, T cells have ___ receptors	CD4 and CD8 receptors
To make a Th1 cell ____ is released. To make Th2, ____ is released	Th1= IL12, Th2 = IL4
TH1 cells secrete ___ and are inhibited by ____.	IL-2, IFN-gamma; inhibited by IL-10
Th2 cells secrete ____ and are inhibited by ___.	IL 4,5, 10; inhibited by IFN gamma
Th2 cells help B cells to secrete antibody ___	IgE> IgG
only lymphocyte member of the immune system	Natural killer cells
Natural killer cells are enhanced by	IL-12, IFN-beta, IFN-a
MHC I are mostly for cells infected with a ___	virus
APCS include ___ and have MHC II receptors	APC = macrophage, dendritic, B cells (MHC II)
in a macrophage-lymphocyte (which one?) interaction, lymphocytes release ___ while macrophages release ___. They stimulate each other	Th1. TH1 release IFN-gamma, macrophages (IL-1, TNF-alpha)
Th2 are infamous for helping cells. Which ones do they help? What signals do they send for each	CTL (IL-2, IFN-gamma), B (IL4, IL5)
MHCI includes HLA- (), MHC II ()_	MHC I (A,B,C), MHC II (DR, DQ, DP)
Ag is loaded on MHC I in ___ and ___ in MHC II	MHC I = RER (intracellular peptides), MHC II = Acidified endosome
B2 is part of MHC__ complex	I
Type I hypersensitivity is mediated by __ cells	B cells (IgE)
Type II (cytotoxicy) is mediated by ___	B cells (IgG)
Type III (Immune complex) is mediated by ___	b cells (IgG)
Hyper acute rejection = ___ cells,	Hyperacute = B cells
Superantigen mechanism	bind to outside of Beta and MHC II complex. Results in release of IFN-gamma from Th1 cells and IL-1, Il-6, TNF alpha from macrophages
Endotoxin directly stimulates ___ and binds to ___	stimulates macrophages and binds to CD14.
Signal 1 (Th), signal 2	MHC II + CD4/TCR; B7 + CD28 (costiumulatory
Signal 1 (TC), Signal 2 (Tc)	MHC I + CD8/TCR; IL-2 stimulates Tc to kill virus
Signal 1 (B), Signal 2 (B)	Th2 cell secretes IL 4,5,6, CD40+CD40 L from Th2
Fc portion of Ig_ and Ig_ fixes complement	G,M
__ determines idiotype, __ determines Isotypes. __ is made from heavy chain	Fab = idiotype, Fc = isotype, Fc =heavy chain
4 ways that antibody diversity is created	1. Random recombination of VJ (light) and VDJ(heavy) chains, 2. random combination of heavy chains with light chains, 3. somatic hypermutation (following ag stimulation-point mutation--> enhances affinity),4. addition of nucleotides during recomibination
terminal deoxynucleotidyl transferase is resopnsible for ____.	addition of nucleotides to DNA during recombination and increasing antibody diversity
Name Ig: opsonization	G
Name Ig: travels across placenta	IgA,IgG
Name Ig: initiate complement	IgG, IgM
Name Ig: initiate neutralization	IgA, IgM, IgG
Name Ig: initiate degranulation	IgE
Diseases associated with rearrangement	Burkitts lymphoma (heavy chain moves to myc with 8, 14, translocation), SCID (lack rearrangement in T and B cells
IL-4 stimulates Ig_	IgE and IgG
IL-5 stimulates Ig_	IgA
Normally a mature b cell has what Ig?	IgM, IgD
Ig_ = prevents attachment of bacteria and viruses, to mucous emmbranes	IgA
Found as a monomer/dimer = Ig_	IgA
Found in secretion	IgA
Lowest concentration in serum	IgE
Ig epitope that differs among same species (polymorphism)	allotypes
Ig epitope common to a single class of Ig	Isotype (IgG, IgE)
Ig epitope determined by antigen binding site	Idiotype = hypervariable region is unique
Ig epitope that differs among same species (polymorphism)	allotypes
Ig epitope common to a single class of Ig	Isotype (IgG, IgE)
Ig epitope determined by antigen binding site	Idiotype = hypervariable region is unique