Immunology Flashcards
3 main parts of a lymph node
Follicle, paracortex, medulla
Follicles
site of B cell localization, primary are dense and dormant
Medulla
contains cords (lymphocytes, plasma cells) and sinuses (communication with efferents, contain reticular macrophages)
Paracortex
close to follicles, contains T cells, high endothelial venules enter here
which region is poorly developed in DiGeorge syndrome?
paracortex
Where are T cells located in spleen?
White pulp, periarteriolar lymphatic sheath
Where are B cells located in spleen?
White pulp, in follicles
Where are APCs located in spleen?
Marginal zone between red and white pulp
Encapsulated organism pneumonic
SHiNE SKiS Strep pneumo Haemophilus influenzae B Neisseria meningititus E Coli Salmonella Klebsiella pneumo Strep pyo (group B)
Why are asplenic individuals susceptible to encapsulated organisms?
Lower IgM –> lower complement activation –> lower C3b opsonization
Peripheral smear findings post splenectomy
Howell Jolly Bodies (no removal of nuclear remnants)
Target cells (HALT)
Thrombocytosis (loss of storage and removal by reticulars)
Lymphocytosis (loss of storage)
Which pharyngeal pouch creates the thymus?
Third
MHC I Loci
HLA-A, HLA-B, and HLA-C
MHC II Loci
HLA-DR, HLA-DP, HLA-DQ
Protein associated w/ MHC I
beta2 microglobulin
Protein associated w/ MHC II
invariant chain
HLA-A3 disease association
Hemochromatosis
HLA-B27 disease association
Psoriatic Arthritis, Anklyosing Spondylitis, IBD, and Reactive Arthritis
HLA-DQ2/8 disease association
Celiac disease
HLA-DR2 disease association
MS, hay fever, SLE, Good Pasture
HLA-DR3 disease association
DM, SLE, Graves, Hashimoto thyroiditis
HLA-DR4 disease association
RA, DM
HLA-DR5 disease association
pernicious anemia (vit b12 deficient)
Natural Killer cell enzymes
granzymes and perforin
TH1 Cells secrete…..
IFN-gamma to activate macrophages and CTLs
TH2 cells secrete….
IL-4, IL-5, IL-10, IL-13
Recruit Eosinophils for parasite defense
Promote IgE production by B cells
Which cytokines activate TH1 cells?
Interferon Gamma and IL-12 (macrophages)
Which cytokines activate TH2 cells?
IL-4
Which ABs are on B cell surfaces?
IgG and IgM
Most common AB in serum?
IgG
First AB made in response to antigen?
IgM
Which AB doesn’t cross placenta?
IgM
Which AB does not fix complement?
IgA
Most produced AB?
IgA
Which AB is involved in Type I Hypersensitivity reactions?
IgE
Which vaccines require adjuvants?
Non-peptide antigens
Which cytokine induces acute phase reactants?
IL-6
C-reactive Protein
Opsonin that fixes complement to facilitate phagocytosis
Ferritin
Binds iron and sequesters in cells to inhibit microbial growth
Fibrinogen
Coagulation factor, also promotes endothelial repair
Correlated to ESR
Hepcidin
Prevents release of iron from ferritin
–> elevated in anemia of chronic disease
Serum Amyloid A
Prolonged elevation leads to amyloidosis…..
Albumin’s relation to acute phase reactants
Might be reduced in order to conserve amino acids for positive reactant production
Transferin (during acute phase reaction)
internalized by macrophages to sequester iron
Where is complement synthesized?
Liver
Classic Pathway mediators
IgG and IgM mediated
Alternative Pathway mediators
microbe surface molecules
Lectin pathway mediators
mannose or other sugars
List of major complement disorders
C1 esterase inhibitor deficiency
C3 deficiency
C5-9 deficiencies
DAF deficiency
C1 esterase inhibitor deficiency
causes angioedema, ACE inhibitors contraindicated
C3 deficiency
Increased risk of pyogenic sinus and respiratory infections
increased type 3 hypersensitivity reactions
C5-9 deficiencies
increased susceptibility to recurrent Neisseria infections
DAF deficiency
complement-mediated hemolysis, paroxysmal nocturnal hemoglobinuria
Cytokines Secreted by Macrophages
IL-1, IL-6, IL-8, IL-12, and TNF-alpha
Pneumonic for remembering what IL-1 to IL-6 do
Hot T-Bone stEAK IL-1: Hot (fever) IL-2: T (T-cells) IL-3: Bone (marrow stim) IL-4: E (IgE) IL-5: A (IgA) IL-6: K (acute phase reactants)
IL-1 functions
fever, endothelial activation for adhesion
IL-6 functions
fever and acute phase proteins
IL-8 functions
Neutrophil chemotaxis
IL-12 functions
Activates NKs, TH1 differentiation
TNF-alpha functions
septic shock, endothelial activation
Cytokines secreted by T cells
IL-2 and IL-3
IL-2 functions
growth of helper Ts, CTLs, regulatory Ts, NKCs
IL-3 functions
bone marrow stimulation
Cytokines from TH1 cells
Interferon gamma
Cytokines form TH2 cells
IL-4, IL-5, and IL-10
IL-4 functions
IgE class switching, TH2 differentiation
IL-5 functions
IgA class switching
IL-10 functions
Attenuates immune response
